ough gold foil support the nuclear model?","back":"It showed that the atom is mostly empty space.","points":1,"mcqOptions":[{"text":"It showed that the atom is mostly empty space.","correct":true,"explanation":"If most alpha particles passed through without deflection, they encountered very little matter or charge. This showed that most of an atom’s volume is empty space around its nucleus."},{"text":"It showed that the atom is mostly solid matter.","correct":false,"explanation":"A mostly solid atom would obstruct or deflect many alpha particles, contrary to the observations. Their mostly straight paths showed that the atom is mostly empty space."},{"text":"It showed that the atom is uniformly positively charged.","correct":false,"explanation":"The experiment showed that positive charge is concentrated in the tiny nucleus, not spread throughout the atom. Most particles passed straight through because the atom is mostly empty space."},{"text":"It showed that the atom is mostly made of electrons.","correct":false,"explanation":"Electrons occupy regions around the nucleus, so the atom is not mostly made of electrons. The lack of deflection showed that most atomic volume is empty space."}]},{"id":"86ec85c7-c084-45cd-87a6-071ab4769e3f","cardType":"basic","front":"What two things did Rutherford's alpha scattering experiment prove about the nucleus?","back":"

It is tiny and dense (contains most mass)
It is positively charged

","points":2,"mcqOptions":[{"text":"

It is tiny and dense (contains most mass)
It is positively charged

","correct":true,"explanation":"The rare large deflections showed that most mass is concentrated in a very small, dense region. Repulsion of positive alpha particles established that this nucleus is positively charged."},{"text":"

It is large and diffuse (fills most space)
It is positively charged

","correct":false,"explanation":"Frequent obstruction would be expected from a large, diffuse nucleus, but most alpha particles passed straight through. The nucleus is tiny and dense, and repulsion shows that it is positively charged."},{"text":"

It is tiny and dense (contains most mass)
It is negatively charged

","correct":false,"explanation":"Alpha particles are positively charged, so their strong deflections were caused by repulsion rather than attraction. The nucleus is therefore tiny and dense and has a positive charge."},{"text":"

It is tiny and diffuse (contains little mass)
It is electrically neutral

","correct":false,"explanation":"The nucleus cannot be low-density or neutral: rare large deflections require concentrated mass and electrostatic repulsion. Rutherford’s evidence therefore established a tiny, dense, positively charged nucleus."}]}]}],"examCountdown":{"examDate":"2027-05-25","paperLabel":"Paper 1"},"intro":"$L3c","title":"Radioactive decay, half-life and uses Flashcards","topicSidebar":"$L3d"}]}],"topicId":"d32039cc-27c6-5a44-bba8-5a91465b456f","walled":"$L3e"}],"$L3f"]