Table: Part of Mendeleev's 1869 periodic table
| Group I | Group II | Group III | Group IV | Group V | Group VI |
|---|---|---|---|---|---|
| Li (7) | Be (9.4) | B (11) | C (12) | N (14) | O (16) |
| Na (23) | Mg (24) | Al (27.3) | Si (28) | P (31) | S (32) |
| K (39) | Ca (40) | — | Ti (48) | V (51) | Cr (52) |
| Cu (63) | Zn (65) | — | — | As (75) | Se (78) |
What strengthened scientific acceptance of Mendeleev's table?
Proof that relative atomic masses are all whole numbers
Discovery that atoms contain electrons
Removal of the gaps from his original table
Discovery of elements with properties close to his predictions
80 exam-style questions on Edexcel GCSE Chemistry 2.2 The periodic table, covering 2.2.1 Mendeleev's periodic table, 2.2.2 Periods, groups, metals and non-metals, and 2.2.3 Electronic configuration and position in the periodic table. Each one has a worked solution and a mark scheme showing where the marks go.