33:I[196793,["/_next/static/chunks/34batdc-i3b0_.js?dpl=nogit-1791217996","/_next/static/chunks/2_6olli-sutu3.js?dpl=nogit-1791217996","/_next/static/chunks/0zcakt1-boe_f.js?dpl=nogit-1791217996","/_next/static/chunks/0yuh9obhrf6py.js?dpl=nogit-1791217996","/_next/static/chunks/3mz725-y91ph6.js?dpl=nogit-1791217996","/_next/static/chunks/2x_dbpl3b_l2r.js?dpl=nogit-1791217996","/_next/static/chunks/13_9hjun60hj-.js?dpl=nogit-1791217996","/_next/static/chunks/2bxmml65nu49g.js?dpl=nogit-1791217996","/_next/static/chunks/0zkcxwtbsqliz.js?dpl=nogit-1791217996","/_next/static/chunks/0d3f1nmeak_z5.js?dpl=nogit-1791217996","/_next/static/chunks/2gjyu-jrwu-fu.js?dpl=nogit-1791217996","/_next/static/chunks/38w1x0vrld4-w.js?dpl=nogit-1791217996","/_next/static/chunks/3jpl-42mbad5n.js?dpl=nogit-1791217996","/_next/static/chunks/3kzt2piec6aoa.js?dpl=nogit-1791217996","/_next/static/chunks/19ijf68pshdcn.js?dpl=nogit-1791217996","/_next/static/chunks/2os7nxouq91eq.js?dpl=nogit-1791217996","/_next/static/chunks/3ml3vooxhiupb.js?dpl=nogit-1791217996","/_next/static/chunks/04zr-wqafvwoa.js?dpl=nogit-1791217996","/_next/static/chunks/10rmxw_yiwj40.js?dpl=nogit-1791217996","/_next/static/chunks/40lyu17d590zu.js?dpl=nogit-1791217996","/_next/static/chunks/2g-t2n9ahs3tn.js?dpl=nogit-1791217996","/_next/static/chunks/1g1suj21ijg7y.js?dpl=nogit-1791217996","/_next/static/chunks/3lz9pr5v38m4h.js?dpl=nogit-1791217996","/_next/static/chunks/2mv9l1xl_aa4j.js?dpl=nogit-1791217996","/_next/static/chunks/0v4byuex1x38h.js?dpl=nogit-1791217996","/_next/static/chunks/2oijhb0tdir9b.js?dpl=nogit-1791217996","/_next/static/chunks/2eanemqjnv2vr.js?dpl=nogit-1791217996","/_next/static/chunks/44nm8-o05iplc.js?dpl=nogit-1791217996","/_next/static/chunks/0llqhg6-bxn_b.js?dpl=nogit-1791217996","/_next/static/chunks/1ku-vdy4ggo41.js?dpl=nogit-1791217996","/_next/static/chunks/2r29ujce72_54.js?dpl=nogit-1791217996","/_next/static/chunks/2dx-vzwyw9a3g.js?dpl=nogit-1791217996","/_next/static/chunks/1coblm1-go81_.js?dpl=nogit-1791217996","/_next/static/chunks/0jt4ynafgg-jc.js?dpl=nogit-1791217996","/_next/static/chunks/0k-y_4mcfub-p.js?dpl=nogit-1791217996","/_next/static/chunks/0qdwqau744_ry.js?dpl=nogit-1791217996","/_next/static/chunks/2eycy5cqzjdqf.js?dpl=nogit-1791217996","/_next/static/chunks/33z1jiacs_jrz.js?dpl=nogit-1791217996","/_next/static/chunks/0w7ow4sfu0tl_.js?dpl=nogit-1791217996","/_next/static/chunks/3it1o0ex-l5qz.js?dpl=nogit-1791217996","/_next/static/chunks/1eyu-5752jh17.js?dpl=nogit-1791217996","/_next/static/chunks/28uw5fp_u1bnm.js?dpl=nogit-1791217996","/_next/static/chunks/3ybwgs28on6c8.js?dpl=nogit-1791217996","/_next/static/chunks/0ixdj_i1afhld.js?dpl=nogit-1791217996","/_next/static/chunks/20_c60cgo1g9g.js?dpl=nogit-1791217996","/_next/static/chunks/075i0tnxt4not.js?dpl=nogit-1791217996","/_next/static/chunks/1lsxkfxy262n-.js?dpl=nogit-1791217996","/_next/static/chunks/2ryoj58czm802.js?dpl=nogit-1791217996","/_next/static/chunks/3v6lxgtmi9vqz.js?dpl=nogit-1791217996","/_next/static/chunks/13gj59kzq50t_.js?dpl=nogit-1791217996","/_next/static/chunks/3q5gc8lbwr4b4.js?dpl=nogit-1791217996","/_next/static/chunks/0wl6wuakgnlec.js?dpl=nogit-1791217996","/_next/static/chunks/30w6c7jj-mxyi.js?dpl=nogit-1791217996","/_next/static/chunks/2qk8b2y5gyu_0.js?dpl=nogit-1791217996","/_next/static/chunks/3lwy4_ovl68-o.js?dpl=nogit-1791217996","/_next/static/chunks/1hnuhh5t7cfaj.js?dpl=nogit-1791217996","/_next/static/chunks/36nndwkz7iik3.js?dpl=nogit-1791217996","/_next/static/chunks/24srd-xd1m5z8.js?dpl=nogit-1791217996","/_next/static/chunks/0zg1om_k0m5zv.js?dpl=nogit-1791217996","/_next/static/chunks/1d7tjnrc0fv5y.js?dpl=nogit-1791217996","/_next/static/chunks/1ksyn9m68446d.js?dpl=nogit-1791217996"],"Gingerbread"] 35:I[647935,["/_next/static/chunks/34batdc-i3b0_.js?dpl=nogit-1791217996","/_next/static/chunks/2_6olli-sutu3.js?dpl=nogit-1791217996","/_next/static/chunks/0zcakt1-boe_f.js?dpl=nogit-1791217996","/_next/static/chunks/0yuh9obhrf6py.js?dpl=nogit-1791217996","/_next/static/chunks/3mz725-y91ph6.js?dpl=nogit-1791217996","/_next/static/chunks/2x_dbpl3b_l2r.js?dpl=nogit-1791217996","/_next/static/chunks/13_9hjun60hj-.js?dpl=nogit-1791217996","/_next/static/chunks/2bxmml65nu49g.js?dpl=nogit-1791217996","/_next/static/chunks/0zkcxwtbsqliz.js?dpl=nogit-1791217996","/_next/static/chunks/0d3f1nmeak_z5.js?dpl=nogit-1791217996","/_next/static/chunks/2gjyu-jrwu-fu.js?dpl=nogit-1791217996","/_next/static/chunks/38w1x0vrld4-w.js?dpl=nogit-1791217996","/_next/static/chunks/3jpl-42mbad5n.js?dpl=nogit-1791217996","/_next/static/chunks/3kzt2piec6aoa.js?dpl=nogit-1791217996","/_next/static/chunks/19ijf68pshdcn.js?dpl=nogit-1791217996","/_next/static/chunks/2os7nxouq91eq.js?dpl=nogit-1791217996","/_next/static/chunks/3ml3vooxhiupb.js?dpl=nogit-1791217996","/_next/static/chunks/04zr-wqafvwoa.js?dpl=nogit-1791217996","/_next/static/chunks/10rmxw_yiwj40.js?dpl=nogit-1791217996","/_next/static/chunks/40lyu17d590zu.js?dpl=nogit-1791217996","/_next/static/chunks/2g-t2n9ahs3tn.js?dpl=nogit-1791217996","/_next/static/chunks/1g1suj21ijg7y.js?dpl=nogit-1791217996","/_next/static/chunks/3lz9pr5v38m4h.js?dpl=nogit-1791217996","/_next/static/chunks/2mv9l1xl_aa4j.js?dpl=nogit-1791217996","/_next/static/chunks/0v4byuex1x38h.js?dpl=nogit-1791217996","/_next/static/chunks/2oijhb0tdir9b.js?dpl=nogit-1791217996","/_next/static/chunks/2eanemqjnv2vr.js?dpl=nogit-1791217996","/_next/static/chunks/44nm8-o05iplc.js?dpl=nogit-1791217996","/_next/static/chunks/0llqhg6-bxn_b.js?dpl=nogit-1791217996","/_next/static/chunks/1ku-vdy4ggo41.js?dpl=nogit-1791217996","/_next/static/chunks/2r29ujce72_54.js?dpl=nogit-1791217996","/_next/static/chunks/2dx-vzwyw9a3g.js?dpl=nogit-1791217996","/_next/static/chunks/1coblm1-go81_.js?dpl=nogit-1791217996","/_next/static/chunks/0jt4ynafgg-jc.js?dpl=nogit-1791217996","/_next/static/chunks/0k-y_4mcfub-p.js?dpl=nogit-1791217996","/_next/static/chunks/0qdwqau744_ry.js?dpl=nogit-1791217996","/_next/static/chunks/2eycy5cqzjdqf.js?dpl=nogit-1791217996","/_next/static/chunks/33z1jiacs_jrz.js?dpl=nogit-1791217996","/_next/static/chunks/0w7ow4sfu0tl_.js?dpl=nogit-1791217996","/_next/static/chunks/3it1o0ex-l5qz.js?dpl=nogit-1791217996","/_next/static/chunks/1eyu-5752jh17.js?dpl=nogit-1791217996","/_next/static/chunks/28uw5fp_u1bnm.js?dpl=nogit-1791217996","/_next/static/chunks/3ybwgs28on6c8.js?dpl=nogit-1791217996","/_next/static/chunks/0ixdj_i1afhld.js?dpl=nogit-1791217996","/_next/static/chunks/20_c60cgo1g9g.js?dpl=nogit-1791217996","/_next/static/chunks/075i0tnxt4not.js?dpl=nogit-1791217996","/_next/static/chunks/1lsxkfxy262n-.js?dpl=nogit-1791217996","/_next/static/chunks/2ryoj58czm802.js?dpl=nogit-1791217996","/_next/static/chunks/3v6lxgtmi9vqz.js?dpl=nogit-1791217996","/_next/static/chunks/13gj59kzq50t_.js?dpl=nogit-1791217996","/_next/static/chunks/3q5gc8lbwr4b4.js?dpl=nogit-1791217996","/_next/static/chunks/0wl6wuakgnlec.js?dpl=nogit-1791217996","/_next/static/chunks/30w6c7jj-mxyi.js?dpl=nogit-1791217996","/_next/static/chunks/2qk8b2y5gyu_0.js?dpl=nogit-1791217996","/_next/static/chunks/3lwy4_ovl68-o.js?dpl=nogit-1791217996","/_next/static/chunks/1hnuhh5t7cfaj.js?dpl=nogit-1791217996","/_next/static/chunks/36nndwkz7iik3.js?dpl=nogit-1791217996","/_next/static/chunks/24srd-xd1m5z8.js?dpl=nogit-1791217996","/_next/static/chunks/0zg1om_k0m5zv.js?dpl=nogit-1791217996","/_next/static/chunks/1d7tjnrc0fv5y.js?dpl=nogit-1791217996","/_next/static/chunks/1ksyn9m68446d.js?dpl=nogit-1791217996"],"RecordResourceResume"] 36:I[830476,["/_next/static/chunks/34batdc-i3b0_.js?dpl=nogit-1791217996","/_next/static/chunks/2_6olli-sutu3.js?dpl=nogit-1791217996","/_next/static/chunks/0zcakt1-boe_f.js?dpl=nogit-1791217996","/_next/static/chunks/0yuh9obhrf6py.js?dpl=nogit-1791217996","/_next/static/chunks/3mz725-y91ph6.js?dpl=nogit-1791217996","/_next/static/chunks/2x_dbpl3b_l2r.js?dpl=nogit-1791217996","/_next/static/chunks/13_9hjun60hj-.js?dpl=nogit-1791217996","/_next/static/chunks/2bxmml65nu49g.js?dpl=nogit-1791217996","/_next/static/chunks/0zkcxwtbsqliz.js?dpl=nogit-1791217996","/_next/static/chunks/0d3f1nmeak_z5.js?dpl=nogit-1791217996","/_next/static/chunks/2gjyu-jrwu-fu.js?dpl=nogit-1791217996","/_next/static/chunks/38w1x0vrld4-w.js?dpl=nogit-1791217996","/_next/static/chunks/3jpl-42mbad5n.js?dpl=nogit-1791217996","/_next/static/chunks/3kzt2piec6aoa.js?dpl=nogit-1791217996","/_next/static/chunks/19ijf68pshdcn.js?dpl=nogit-1791217996","/_next/static/chunks/2os7nxouq91eq.js?dpl=nogit-1791217996","/_next/static/chunks/3ml3vooxhiupb.js?dpl=nogit-1791217996","/_next/static/chunks/04zr-wqafvwoa.js?dpl=nogit-1791217996","/_next/static/chunks/10rmxw_yiwj40.js?dpl=nogit-1791217996","/_next/static/chunks/40lyu17d590zu.js?dpl=nogit-1791217996","/_next/static/chunks/2g-t2n9ahs3tn.js?dpl=nogit-1791217996","/_next/static/chunks/1g1suj21ijg7y.js?dpl=nogit-1791217996","/_next/static/chunks/3lz9pr5v38m4h.js?dpl=nogit-1791217996","/_next/static/chunks/2mv9l1xl_aa4j.js?dpl=nogit-1791217996","/_next/static/chunks/0v4byuex1x38h.js?dpl=nogit-1791217996","/_next/static/chunks/2oijhb0tdir9b.js?dpl=nogit-1791217996","/_next/static/chunks/2eanemqjnv2vr.js?dpl=nogit-1791217996","/_next/static/chunks/44nm8-o05iplc.js?dpl=nogit-1791217996","/_next/static/chunks/0llqhg6-bxn_b.js?dpl=nogit-1791217996","/_next/static/chunks/1ku-vdy4ggo41.js?dpl=nogit-1791217996","/_next/static/chunks/2r29ujce72_54.js?dpl=nogit-1791217996","/_next/static/chunks/2dx-vzwyw9a3g.js?dpl=nogit-1791217996","/_next/static/chunks/1coblm1-go81_.js?dpl=nogit-1791217996","/_next/static/chunks/0jt4ynafgg-jc.js?dpl=nogit-1791217996","/_next/static/chunks/0k-y_4mcfub-p.js?dpl=nogit-1791217996","/_next/static/chunks/0qdwqau744_ry.js?dpl=nogit-1791217996","/_next/static/chunks/2eycy5cqzjdqf.js?dpl=nogit-1791217996","/_next/static/chunks/33z1jiacs_jrz.js?dpl=nogit-1791217996","/_next/static/chunks/0w7ow4sfu0tl_.js?dpl=nogit-1791217996","/_next/static/chunks/3it1o0ex-l5qz.js?dpl=nogit-1791217996","/_next/static/chunks/1eyu-5752jh17.js?dpl=nogit-1791217996","/_next/static/chunks/28uw5fp_u1bnm.js?dpl=nogit-1791217996","/_next/static/chunks/3ybwgs28on6c8.js?dpl=nogit-1791217996","/_next/static/chunks/0ixdj_i1afhld.js?dpl=nogit-1791217996","/_next/static/chunks/20_c60cgo1g9g.js?dpl=nogit-1791217996","/_next/static/chunks/075i0tnxt4not.js?dpl=nogit-1791217996","/_next/static/chunks/1lsxkfxy262n-.js?dpl=nogit-1791217996","/_next/static/chunks/2ryoj58czm802.js?dpl=nogit-1791217996","/_next/static/chunks/3v6lxgtmi9vqz.js?dpl=nogit-1791217996","/_next/static/chunks/13gj59kzq50t_.js?dpl=nogit-1791217996","/_next/static/chunks/3q5gc8lbwr4b4.js?dpl=nogit-1791217996","/_next/static/chunks/0wl6wuakgnlec.js?dpl=nogit-1791217996","/_next/static/chunks/30w6c7jj-mxyi.js?dpl=nogit-1791217996","/_next/static/chunks/2qk8b2y5gyu_0.js?dpl=nogit-1791217996","/_next/static/chunks/3lwy4_ovl68-o.js?dpl=nogit-1791217996","/_next/static/chunks/1hnuhh5t7cfaj.js?dpl=nogit-1791217996","/_next/static/chunks/36nndwkz7iik3.js?dpl=nogit-1791217996","/_next/static/chunks/24srd-xd1m5z8.js?dpl=nogit-1791217996","/_next/static/chunks/0zg1om_k0m5zv.js?dpl=nogit-1791217996","/_next/static/chunks/1d7tjnrc0fv5y.js?dpl=nogit-1791217996","/_next/static/chunks/1ksyn9m68446d.js?dpl=nogit-1791217996"],"FlashcardAccessBranch"] 37:I[315438,["/_next/static/chunks/34batdc-i3b0_.js?dpl=nogit-1791217996","/_next/static/chunks/2_6olli-sutu3.js?dpl=nogit-1791217996","/_next/static/chunks/0zcakt1-boe_f.js?dpl=nogit-1791217996","/_next/static/chunks/0yuh9obhrf6py.js?dpl=nogit-1791217996","/_next/static/chunks/3mz725-y91ph6.js?dpl=nogit-1791217996","/_next/static/chunks/2x_dbpl3b_l2r.js?dpl=nogit-1791217996","/_next/static/chunks/13_9hjun60hj-.js?dpl=nogit-1791217996","/_next/static/chunks/2bxmml65nu49g.js?dpl=nogit-1791217996","/_next/static/chunks/0zkcxwtbsqliz.js?dpl=nogit-1791217996","/_next/static/chunks/0d3f1nmeak_z5.js?dpl=nogit-1791217996","/_next/static/chunks/2gjyu-jrwu-fu.js?dpl=nogit-1791217996","/_next/static/chunks/38w1x0vrld4-w.js?dpl=nogit-1791217996","/_next/static/chunks/3jpl-42mbad5n.js?dpl=nogit-1791217996","/_next/static/chunks/3kzt2piec6aoa.js?dpl=nogit-1791217996","/_next/static/chunks/19ijf68pshdcn.js?dpl=nogit-1791217996","/_next/static/chunks/2os7nxouq91eq.js?dpl=nogit-1791217996","/_next/static/chunks/3ml3vooxhiupb.js?dpl=nogit-1791217996","/_next/static/chunks/04zr-wqafvwoa.js?dpl=nogit-1791217996","/_next/static/chunks/10rmxw_yiwj40.js?dpl=nogit-1791217996","/_next/static/chunks/40lyu17d590zu.js?dpl=nogit-1791217996","/_next/static/chunks/2g-t2n9ahs3tn.js?dpl=nogit-1791217996","/_next/static/chunks/1g1suj21ijg7y.js?dpl=nogit-1791217996","/_next/static/chunks/3lz9pr5v38m4h.js?dpl=nogit-1791217996","/_next/static/chunks/2mv9l1xl_aa4j.js?dpl=nogit-1791217996","/_next/static/chunks/0v4byuex1x38h.js?dpl=nogit-1791217996","/_next/static/chunks/2oijhb0tdir9b.js?dpl=nogit-1791217996","/_next/static/chunks/2eanemqjnv2vr.js?dpl=nogit-1791217996","/_next/static/chunks/44nm8-o05iplc.js?dpl=nogit-1791217996","/_next/static/chunks/0llqhg6-bxn_b.js?dpl=nogit-1791217996","/_next/static/chunks/1ku-vdy4ggo41.js?dpl=nogit-1791217996","/_next/static/chunks/2r29ujce72_54.js?dpl=nogit-1791217996","/_next/static/chunks/2dx-vzwyw9a3g.js?dpl=nogit-1791217996","/_next/static/chunks/1coblm1-go81_.js?dpl=nogit-1791217996","/_next/static/chunks/0jt4ynafgg-jc.js?dpl=nogit-1791217996","/_next/static/chunks/0k-y_4mcfub-p.js?dpl=nogit-1791217996","/_next/static/chunks/0qdwqau744_ry.js?dpl=nogit-1791217996","/_next/static/chunks/2eycy5cqzjdqf.js?dpl=nogit-1791217996","/_next/static/chunks/33z1jiacs_jrz.js?dpl=nogit-1791217996","/_next/static/chunks/0w7ow4sfu0tl_.js?dpl=nogit-1791217996","/_next/static/chunks/3it1o0ex-l5qz.js?dpl=nogit-1791217996","/_next/static/chunks/1eyu-5752jh17.js?dpl=nogit-1791217996","/_next/static/chunks/28uw5fp_u1bnm.js?dpl=nogit-1791217996","/_next/static/chunks/3ybwgs28on6c8.js?dpl=nogit-1791217996","/_next/static/chunks/0ixdj_i1afhld.js?dpl=nogit-1791217996","/_next/static/chunks/20_c60cgo1g9g.js?dpl=nogit-1791217996","/_next/static/chunks/075i0tnxt4not.js?dpl=nogit-1791217996","/_next/static/chunks/1lsxkfxy262n-.js?dpl=nogit-1791217996","/_next/static/chunks/2ryoj58czm802.js?dpl=nogit-1791217996","/_next/static/chunks/3v6lxgtmi9vqz.js?dpl=nogit-1791217996","/_next/static/chunks/13gj59kzq50t_.js?dpl=nogit-1791217996","/_next/static/chunks/3q5gc8lbwr4b4.js?dpl=nogit-1791217996","/_next/static/chunks/0wl6wuakgnlec.js?dpl=nogit-1791217996","/_next/static/chunks/30w6c7jj-mxyi.js?dpl=nogit-1791217996","/_next/static/chunks/2qk8b2y5gyu_0.js?dpl=nogit-1791217996","/_next/static/chunks/3lwy4_ovl68-o.js?dpl=nogit-1791217996","/_next/static/chunks/1hnuhh5t7cfaj.js?dpl=nogit-1791217996","/_next/static/chunks/36nndwkz7iik3.js?dpl=nogit-1791217996","/_next/static/chunks/24srd-xd1m5z8.js?dpl=nogit-1791217996","/_next/static/chunks/0zg1om_k0m5zv.js?dpl=nogit-1791217996","/_next/static/chunks/1d7tjnrc0fv5y.js?dpl=nogit-1791217996","/_next/static/chunks/1ksyn9m68446d.js?dpl=nogit-1791217996"],"TopicFlashcardRunner"] 24:[["$","$L33",null,{"feature":"flashcards"}],"$L34",["$","$L35",null,{"href":"/a-level/chemistry/ocr/a/atomic-structure-and-isotopes/flashcards","label":"Atomic structure and isotopes","subjectCode":"a_level_chemistry__ocr_a","surface":"flashcards"}],["$","$L36",null,{"runner":["$","div",null,{"className":"min-h-0 flex-1 overflow-hidden bg-background","children":["$","$L37",null,{"decks":[{"id":"aa804127-fb2c-4224-b200-66bc44702378","title":"Atomic structure and isotopes Flashcards","topicId":"d88fc8b9-7df9-5b0e-9ff0-804962981bff","topicSlug":"atomic-structure-and-isotopes","cards":[{"id":"86f28feb-6325-42b8-a459-fac5a5a0c7ba","cardType":"basic","points":1,"front":"What feature decides which element an atom is?","back":"The number of protons in the nucleus.","mcqOptions":[{"text":"The number of protons in the nucleus.","correct":true,"explanation":"An element is defined by its proton number, also called its atomic number. Changing the number of protons produces an atom of a different element."},{"text":"The number of neutrons in the nucleus.","correct":false,"explanation":"Changing the neutron number creates a different isotope, not a different element. The element’s identity is determined by the number of protons in its nucleus."},{"text":"The number of electrons around the nucleus.","correct":false,"explanation":"The electron number can change when an atom forms an ion without changing its element. Element identity depends on the number of protons in the nucleus."},{"text":"The number of nucleons in the nucleus.","correct":false,"explanation":"The nucleon number is the combined number of protons and neutrons, so it can differ between isotopes. Only the number of protons determines the element."}]},{"id":"5796ac64-4679-4709-b8b9-ddad14fc832d","cardType":"cloze","points":null,"front":"In nuclide notation, the atomic number $Z$ gives the number of [ ].","back":"In nuclide notation, the atomic number $Z$ gives the number of protons.","mcqOptions":[{"text":"protons","correct":true,"explanation":"The atomic number $Z$ is defined as the number of protons in an atom’s nucleus. It therefore uniquely identifies the element."},{"text":"neutrons","correct":false,"explanation":"The neutron number can vary between isotopes of the same element and is calculated using $A-Z$. The atomic number $Z$ gives the number of protons."},{"text":"electrons","correct":false,"explanation":"In a neutral atom the electron number equals $Z$, but ions have different electron numbers. By definition, $Z$ always gives the number of protons."},{"text":"nucleons","correct":false,"explanation":"Nucleons include both protons and neutrons, and their total is the mass number $A$. The atomic number $Z$ counts protons only."}]},{"id":"ab949f47-1e2c-42f4-81f0-1921dca78dc8","cardType":"cloze","points":null,"front":"The mass number $A$ is the total number of [ ] and [ ].","back":"The mass number $A$ is the total number of protons and neutrons.","mcqOptions":[{"text":"The mass number $A$ is the total number of protons and neutrons.","correct":true,"explanation":"Protons and neutrons are the nucleons found in the nucleus. Their combined total is the mass number, so $A=Z+N$."},{"text":"The mass number $A$ is the total number of protons and electrons.","correct":false,"explanation":"Electrons have negligible mass and are not included in the mass number. The mass number $A$ is the total number of protons and neutrons."},{"text":"The mass number $A$ is the total number of electrons and neutrons.","correct":false,"explanation":"This substitutes electrons for protons, but mass number counts particles in the nucleus. It is the combined number of protons and neutrons."},{"text":"The mass number $A$ is the total number of neutrons and electrons.","correct":false,"explanation":"Counting neutrons and electrons omits the nuclear protons and incorrectly includes extranuclear particles. Mass number is the total of protons and neutrons."}]},{"id":"9766f0e7-9423-44c4-89b7-76c97185a554","cardType":"basic","points":1,"front":"In ${}^{A}_{Z}\\text{X}$, how do you calculate the number of neutrons?","back":"$A - Z$.","mcqOptions":[{"text":"$A - Z$.","correct":true,"explanation":"The mass number $A$ equals protons plus neutrons, while $Z$ equals protons. Subtracting gives the neutron number: $N=A-Z$."},{"text":"$A + Z$.","correct":false,"explanation":"Adding $Z$ counts the protons twice because they are already included in $A$. The number of neutrons is found by subtracting: $A-Z$."},{"text":"$Z - A$.","correct":false,"explanation":"This reverses the subtraction and would usually produce an impossible negative neutron number. Since $A=Z+N$, the correct rearrangement is $N=A-Z$."},{"text":"$A \\div Z$.","correct":false,"explanation":"Dividing mass number by atomic number gives a ratio, not a particle count. Neutrons are the nucleons remaining after subtracting protons, so use $A-Z$."}]},{"id":"5653ac27-cb71-433a-9c1a-7beac42ce5ea","cardType":"basic","points":1,"front":"For a neutral atom, how many electrons are there?","back":"The same number as protons.","mcqOptions":[{"text":"The same number as protons.","correct":true,"explanation":"A neutral atom has zero overall charge, so its negative electrons must exactly balance its positive protons. Their numbers are therefore equal."},{"text":"The same number as neutrons.","correct":false,"explanation":"Neutrons carry no charge and do not determine electrical neutrality. A neutral atom has equal numbers of negatively charged electrons and positively charged protons."},{"text":"The same number as nucleons.","correct":false,"explanation":"The nucleon number includes both protons and neutrons, so it does not determine electron number. Neutrality requires the number of electrons to equal the number of protons."},{"text":"One fewer than protons.","correct":false,"explanation":"Having one fewer electron than protons would give the particle a $+1$ charge. A neutral atom instead has exactly the same number of electrons as protons."}]},{"id":"4c190288-f5ab-4cb8-bb45-0675eaea9776","cardType":"basic","points":1,"front":"A positive ion has formed. What happened to its electrons?","back":"It has lost electrons.","mcqOptions":[{"text":"It has lost electrons.","correct":true,"explanation":"Losing negatively charged electrons leaves more protons than electrons, producing an overall positive charge. The nucleus remains unchanged during ordinary ion formation."},{"text":"It has gained electrons.","correct":false,"explanation":"Gaining negative electrons would produce a negative ion rather than a positive one. A positive ion forms when an atom loses one or more electrons."},{"text":"It has lost protons.","correct":false,"explanation":"Losing positive protons would not explain a positive charge and would change the element’s identity. Positive ions form by losing negatively charged electrons."},{"text":"It has gained protons.","correct":false,"explanation":"Adding protons could increase positive charge, but it is a nuclear change that creates a different element. Ordinary positive ion formation occurs through electron loss."}]},{"id":"de74906a-639b-4c77-a9d2-66d93fa80b28","cardType":"basic","points":1,"front":"A negative ion has formed. What happened to its electrons?","back":"It has gained electrons.","mcqOptions":[{"text":"It has gained electrons.","correct":true,"explanation":"Gaining negatively charged electrons gives the particle more electrons than protons, producing an overall negative charge without changing its nucleus."},{"text":"It has lost electrons.","correct":false,"explanation":"Losing negative electrons leaves an excess of positive charge and forms a positive ion. A negative ion is produced when an atom gains electrons."},{"text":"It has gained protons.","correct":false,"explanation":"Gaining positively charged protons would not produce a negative ion and would change the element. Negative ions form by gaining negatively charged electrons."},{"text":"It has lost protons.","correct":false,"explanation":"Removing protons is a nuclear change that alters the element’s identity, not ordinary ion formation. A negative ion forms when electrons are gained."}]},{"id":"3467af96-de88-4252-aa5a-17be7af8b2e7","cardType":"cloze","points":null,"front":"When ions form, atoms lose or gain [ ]; protons and neutrons stay unchanged.","back":"When ions form, atoms lose or gain electrons; protons and neutrons stay unchanged.","mcqOptions":[{"text":"electrons","correct":true,"explanation":"Ion formation involves transferring electrons, which changes the balance between positive and negative charge. The numbers of protons and neutrons in the nucleus remain unchanged."},{"text":"protons","correct":false,"explanation":"Changing the proton number would change the element’s identity and requires a nuclear process. Atoms form ions by losing or gaining electrons instead."},{"text":"neutrons","correct":false,"explanation":"Changing neutron number creates a different isotope and does not directly produce the usual ionic charge. Ion formation occurs through the loss or gain of electrons."},{"text":"nucleons","correct":false,"explanation":"Nucleons are protons and neutrons within the nucleus, and changing them is a nuclear process. Ordinary ion formation changes only the number of electrons."}]},{"id":"2bb92488-622e-4377-b2b5-87455ae24b87","cardType":"basic","points":1,"front":"In ${}^{27}_{13}\\text{Al}^{3+}$, how many electrons are present?","back":"10 electrons.","mcqOptions":[{"text":"10 electrons.","correct":true,"explanation":"A neutral aluminium atom has 13 electrons. The $3+$ charge means it has lost three electrons, leaving $13 - 3 = 10$ electrons."},{"text":"13 electrons.","correct":false,"explanation":"Thirteen is the electron count for a neutral aluminium atom. The $3+$ ion has lost three electrons, so it contains 10 electrons."},{"text":"16 electrons.","correct":false,"explanation":"Adding three electrons reverses the meaning of the positive charge. A $3+$ ion has lost three from aluminium’s original 13, leaving 10 electrons."},{"text":"14 electrons.","correct":false,"explanation":"Subtracting the atomic number from the mass number gives 14 neutrons, not electrons. The $3+$ aluminium ion has $13 - 3 = 10$ electrons."}]},{"id":"5ef67b20-22bc-4031-b86f-b6b385c6f495","cardType":"basic","points":2,"front":"How can you tell quickly that two atoms are isotopes?","back":"Same atomic number, different mass numbers.","mcqOptions":[{"text":"Same atomic number, different mass numbers.","correct":true,"explanation":"Isotopes are atoms of the same element, so they have equal numbers of protons and therefore the same atomic number, but different neutron counts produce different mass numbers."},{"text":"Different atomic numbers, same mass number.","correct":false,"explanation":"Different atomic numbers mean different numbers of protons, so the atoms are different elements rather than isotopes. Isotopes have the same atomic number but different mass numbers."},{"text":"Same mass number, different atomic numbers.","correct":false,"explanation":"Atoms sharing a mass number but having different atomic numbers are isobars, not isotopes. Isotopes share an atomic number and have different mass numbers."},{"text":"Same atomic number, same mass number.","correct":false,"explanation":"Matching both numbers describes the same nuclide, not two different isotopes. Isotopes have the same atomic number but different mass numbers because their neutron counts differ."}]},{"id":"210517f0-15c6-46e1-a5ec-d38656b6c2e8","cardType":"cloze","points":null,"front":"Isotopes have the same number of [ ] but different numbers of [ ].","back":"Isotopes have the same number of protons but different numbers of neutrons.","mcqOptions":[{"text":"Isotopes have the same number of protons but different numbers of neutrons.","correct":true,"explanation":"An element is defined by its proton number, so all its isotopes have the same number of protons. Their differing neutron numbers give them different mass numbers."},{"text":"Isotopes have the same number of neutrons but different numbers of protons.","correct":false,"explanation":"Reversing the particles would make the atoms different elements because proton number determines identity. Isotopes instead have equal proton numbers and different neutron numbers."},{"text":"Isotopes have the same number of electrons but different numbers of protons.","correct":false,"explanation":"Electron number can change when ions form, while different proton numbers identify different elements. Isotopes must have the same number of protons but different numbers of neutrons."},{"text":"Isotopes have the same number of protons but different numbers of electrons.","correct":false,"explanation":"Atoms with equal proton numbers but different electron numbers are different ions, not isotopes. Isotopes differ in neutron number while retaining the same proton number."}]},{"id":"0a5475a1-5317-4e8a-8fb7-91fe5b5edc19","cardType":"basic","points":1,"front":"Which evidence led to Rutherford's nuclear model?","back":"Alpha-scattering evidence.","mcqOptions":[{"text":"Alpha-scattering evidence.","correct":true,"explanation":"Most alpha particles passed through the foil, but a few were strongly deflected. This showed that atoms contain a tiny, dense, positively charged nucleus."},{"text":"Line-emission evidence.","correct":false,"explanation":"Line-emission spectra support quantised electron energy levels rather than Rutherford’s nuclear model. The nuclear model arose from alpha-scattering results, especially rare large deflections."},{"text":"Cathode-ray evidence.","correct":false,"explanation":"Cathode-ray experiments led Thomson to discover the electron and propose the plum pudding model. Rutherford’s nuclear model was instead supported by alpha-scattering evidence."},{"text":"Mass-spectrometry evidence.","correct":false,"explanation":"Mass spectrometry provides evidence about isotopes and their relative abundances, not the original nuclear model. Rutherford used alpha-scattering evidence to infer a concentrated nucleus."}]},{"id":"97369544-8b28-4319-8b99-78f0d3a935b1","cardType":"cloze","points":null,"front":"Relative isotopic mass compares one atom of an isotope with [ ] of the mass of [ ].","back":"Relative isotopic mass compares one atom of an isotope with one-twelfth of the mass of carbon-12.","mcqOptions":[{"text":"Relative isotopic mass compares one atom of an isotope with one-twelfth of the mass of carbon-12.","correct":true,"explanation":"The relative isotopic mass scale is defined using one-twelfth of the mass of a carbon-12 atom as its reference, giving relative masses no units."},{"text":"Relative isotopic mass compares one atom of an isotope with one-sixth of the mass of carbon-12.","correct":false,"explanation":"Using one-sixth would make the reference mass twice as large and halve all relative values. The defined standard is one-twelfth of a carbon-12 atom’s mass."},{"text":"Relative isotopic mass compares one atom of an isotope with one-twelfth of the mass of carbon-14.","correct":false,"explanation":"Carbon-14 is radioactive and is not the reference nuclide for relative masses. The standard is one-twelfth of the mass of a carbon-12 atom."},{"text":"Relative isotopic mass compares one atom of an isotope with one-half of the mass of hydrogen-1.","correct":false,"explanation":"Hydrogen was used in older mass scales, but the modern standard is not based on half a hydrogen-1 atom. It uses one-twelfth of carbon-12."}]},{"id":"4a3836c7-74c3-4eac-891d-5fd3880af0c5","cardType":"cloze","points":null,"front":"Relative atomic mass, $A_r$, is a [ ], so more abundant isotopes affect it more.","back":"Relative atomic mass, $A_r$, is a weighted mean, so more abundant isotopes affect it more.","mcqOptions":[{"text":"weighted mean","correct":true,"explanation":"$$A_r$ combines the relative isotopic masses according to their abundances. Weighting ensures that a more abundant isotope contributes more strongly to the final average."},{"text":"simple mean","correct":false,"explanation":"A simple mean treats every isotope as equally abundant, which is generally untrue. $A_r$ is a weighted mean that accounts for each isotope’s relative abundance."},{"text":"modal value","correct":false,"explanation":"The mode would identify only the most abundant isotope and ignore contributions from all others. $A_r$ is instead the weighted mean of isotopic masses."},{"text":"whole number","correct":false,"explanation":"$$A_r$ is often not a whole number because several isotopes contribute in unequal proportions. It is calculated as a weighted mean using isotopic abundances."}]},{"id":"cec1af00-f1d1-477f-bd62-b19979b333c4","cardType":"basic","points":2,"front":"Why do relative masses have no units?","back":"They are ratios comparing one mass with another.","mcqOptions":[{"text":"They are ratios comparing one mass with another.","correct":true,"explanation":"A relative mass divides one mass by a reference mass measured in the same units. The units cancel in the ratio, leaving a dimensionless value."},{"text":"They are averages calculated without measuring mass.","correct":false,"explanation":"Relative masses are based on measured masses, even when an average is calculated. They lack units because they are ratios to a reference mass, so the units cancel."},{"text":"They are counts of particles inside each atom.","correct":false,"explanation":"Relative masses are not particle counts, although proton and neutron numbers influence mass. They are ratios comparing an atomic mass with a reference mass, causing units to cancel."},{"text":"They are constants defined independently of mass.","correct":false,"explanation":"Relative masses depend on comparisons between measured masses rather than being unrelated constants. Their units cancel because both quantities in the ratio use the same mass unit."}]},{"id":"d8ac0b2f-7dbc-4b99-b7d7-f19515a72b62","cardType":"basic","points":2,"front":"Why is $A_r$ often a decimal rather than a whole number?","back":"It is a weighted mean of naturally occurring isotopes.","mcqOptions":[{"text":"It is a weighted mean of naturally occurring isotopes.","correct":true,"explanation":"Most elements occur as mixtures of isotopes with different masses and abundances. Their abundance-weighted mean commonly lies between the isotopic mass values, producing a decimal."},{"text":"It is a simple mean of protons and neutrons.","correct":false,"explanation":"$$A_r$ is not calculated by averaging particle counts. It is the weighted mean of naturally occurring isotopic masses, accounting for each isotope’s abundance."},{"text":"It is a mass number divided by atomic number.","correct":false,"explanation":"Dividing mass number by atomic number does not define $A_r$. The decimal usually results from taking an abundance-weighted mean of the element’s naturally occurring isotopes."},{"text":"It is a proton count adjusted for electron mass.","correct":false,"explanation":"Proton number is an integer and electron mass is too small to explain the usual decimal. $A_r$ is a weighted mean of naturally occurring isotopes."}]},{"id":"125ab6d8-6ec2-4ea5-8eec-fd1304e5b915","cardType":"basic","points":1,"front":"Besides relative isotopic masses, what isotope data can a mass spectrometer find?","back":"Relative abundances.","mcqOptions":[{"text":"Relative abundances.","correct":true,"explanation":"A mass spectrometer separates ions according to their mass-to-charge ratios and records the relative abundance of each isotope, showing how common each isotopic peak is."},{"text":"Relative atomic numbers","correct":false,"explanation":"Atomic number is fixed by the number of protons and is not measured as isotope peak data. The spectrum instead provides relative abundances, showing the proportion of each isotope."},{"text":"Relative molecular masses","correct":false,"explanation":"Molecular mass is calculated from the atoms present rather than obtained as isotope peak data. A mass spectrum gives relative abundances alongside the relative isotopic masses of detected ions."},{"text":"Relative charges","correct":false,"explanation":"Ion charge affects the measured $m/z$ value but is not the isotope data being sought here. The additional isotope information is relative abundance, indicating the intensity of each peak."}]},{"id":"ee27a1ca-e914-4dcd-9f64-0b64e8279d97","cardType":"basic","points":1,"front":"For single charged ions in these calculations, what can $m/z$ be treated as?","back":"The relative isotopic mass.","mcqOptions":[{"text":"The relative isotopic mass.","correct":true,"explanation":"For a singly charged ion, $z = 1$, so $m/z = m$. The measured value can therefore be treated as the ion’s relative isotopic mass in these calculations."},{"text":"The relative atomic mass.","correct":false,"explanation":"Relative atomic mass is a weighted mean for an element’s naturally occurring isotopes, not the mass of one isotope. For a single charged ion, $m/z$ corresponds to its relative isotopic mass."},{"text":"The mass number.","correct":false,"explanation":"Mass number is the integer total of protons and neutrons, whereas isotope masses are not usually exact integers. For a singly charged ion, $m/z$ is treated as its relative isotopic mass."},{"text":"The relative molecular mass.","correct":false,"explanation":"Relative molecular mass applies to an entire molecule and is found by summing atomic masses. A single charged isotope ion gives an $m/z$ value treated as its relative isotopic mass."}]},{"id":"820b7ae4-f802-4666-9446-3ba039e46d97","cardType":"cloze","points":null,"front":"To calculate $A_r$ from isotope data: multiply each isotopic mass by its [ ], add, then divide by the total abundance.","back":"To calculate $A_r$ from isotope data: multiply each isotopic mass by its relative abundance, add, then divide by the total abundance.","mcqOptions":[{"text":"relative abundance","correct":true,"explanation":"Each isotopic mass must be weighted by how abundant that isotope is. Adding these products and dividing by the total abundance gives the weighted mean, $A_r$."},{"text":"percentage abundance","correct":false,"explanation":"Percentage abundance can be used only if the calculation consistently accounts for the percentage scale, but the standard term in this method is relative abundance. The products are then divided by total abundance."},{"text":"mass number","correct":false,"explanation":"Mass number counts protons and neutrons and does not indicate how common an isotope is. Calculating $A_r$ requires multiplying each isotopic mass by its relative abundance."},{"text":"relative atomic mass","correct":false,"explanation":"Relative atomic mass is the weighted mean being calculated, so using it as the weighting factor is circular. The required factor for each isotope is its relative abundance."}]},{"id":"0de221cf-4f44-4f1a-b661-b1ba77887290","cardType":"basic","points":2,"front":"Calculate $A_r$ for Mg: 24 is 78.6%, 25 is 10.1%, 26 is 11.3%.","back":"24.3.","mcqOptions":[{"text":"24.3.","correct":true,"explanation":"The weighted mean is $(24 \\times 78.6 + 25 \\times 10.1 + 26 \\times 11.3) / 100 = 24.327$, which rounds to $24.3$."},{"text":"24.2.","correct":false,"explanation":"This is a near-miss caused by inaccurate weighting or premature rounding. Using all three isotope abundances gives $24.327$, which rounds correctly to $24.3$."},{"text":"24.5.","correct":false,"explanation":"This overestimates the result by giving the less abundant heavier isotopes too much influence. The abundance-weighted calculation is $24.327$, so the relative atomic mass is $24.3$."},{"text":"25.0.","correct":false,"explanation":"This resembles taking an unweighted average or choosing a middle isotope rather than applying the abundances. Weighting the isotope masses gives $24.327$, which rounds to $24.3$."}]},{"id":"abf6f3cf-d5f7-49aa-a41a-c93e4ee58303","cardType":"basic","points":1,"front":"How is $M_r$ found for a molecule?","back":"Add the $A_r$ values for all atoms in the molecule.","mcqOptions":[{"text":"Add the $A_r$ values for all atoms in the molecule.","correct":true,"explanation":"A molecule’s relative molecular mass is found by adding the relative atomic mass of every atom present, including repeated atoms indicated by subscripts."},{"text":"Multiply the $A_r$ values for all atoms in the molecule.","correct":false,"explanation":"Multiplication does not give the mass of a collection of atoms. The correct method is to add the $A_r$ value for every atom, counting repeated atoms from the formula."},{"text":"Add the mass numbers for all atoms in the molecule.","correct":false,"explanation":"Mass numbers are whole-number isotope values and are not the relative masses used for molecular calculations. The correct method adds the $A_r$ values for all atoms present."},{"text":"Add the $A_r$ values for only the different elements in the molecule.","correct":false,"explanation":"Ignoring subscripts omits repeated atoms and makes the total too small. Every atom must be included, so the correct method adds all the relevant $A_r$ values."}]},{"id":"6a79f624-d512-4894-b2a7-aa9e87e66f43","cardType":"basic","points":1,"front":"Which term is used for giant structures such as NaCl instead of $M_r$?","back":"Relative formula mass.","mcqOptions":[{"text":"Relative formula mass.","correct":true,"explanation":"Ionic compounds such as NaCl form giant lattices rather than discrete molecules, so their mass is described using relative formula mass, based on one formula unit."},{"text":"Relative molecular mass.","correct":false,"explanation":"NaCl does not consist of separate molecules; it forms a giant ionic lattice. Therefore its mass is called relative formula mass rather than relative molecular mass."},{"text":"Relative atomic mass.","correct":false,"explanation":"Relative atomic mass describes a single element’s atoms and their isotopic abundance. NaCl contains ions in a giant structure, so the appropriate term is relative formula mass."},{"text":"Relative isotopic mass.","correct":false,"explanation":"Relative isotopic mass refers to one isotope, not the combined composition of an ionic compound. For a giant structure such as NaCl, the correct term is relative formula mass."}]},{"id":"c23d51a4-a1f7-4ef3-8f9a-31a3c44a73aa","cardType":"basic","points":2,"front":"Calculate the relative formula mass of Mg(NO₃)₂ using $A_r$: Mg = 24.3, N = 14.0, O = 16.0.","back":"148.3.","mcqOptions":[{"text":"148.3.","correct":true,"explanation":"There are one Mg, two N and six O atoms: $24.3 + (2 \\times 14.0) + (6 \\times 16.0) = 148.3$."},{"text":"120.3.","correct":false,"explanation":"This results from counting only four oxygen atoms instead of the six required by $(NO_3)_2$. The correct calculation is $24.3 + 28.0 + 96.0 = 148.3$."},{"text":"134.3.","correct":false,"explanation":"This is an off-by-one oxygen error, using five oxygen atoms rather than six. The subscript 2 applies to the whole nitrate group, giving six oxygens and a total of $148.3$."},{"text":"172.3.","correct":false,"explanation":"This comes from treating the formula as though it contained three nitrate groups, adding seven oxygens. The subscript 2 gives two nitrate groups, so the correct relative formula mass is $148.3$."}]}]}],"examCountdown":{"examDate":"2027-05-28","paperLabel":"Paper 1"},"heading":"Atomic structure and isotopes","title":"Atomic structure and isotopes Flashcards","topbar":{"backHref":"/a-level/chemistry/ocr/a/flashcards"},"topicSidebar":"$L38"}]}],"topicId":"d88fc8b9-7df9-5b0e-9ff0-804962981bff","walled":"$L39"}],"$L3a","$L3b"]