A study modelled the development of classifications of the elements.
Researchers withheld all the data for 8 of 58 elements. They used the data for the remaining 50 elements to produce two classifications. The withheld data were then revealed and the researchers tried to add the eight elements without changing the original positions of the other elements.
| Method | Basis of classification | Number of empty positions left | Number of the 50 elements placed in columns with similar chemical properties | Number of withheld elements added to a suitable column without moving an original element |
|---|---|---|---|---|
| A | Increasing atomic weight only | 0 | 40 | 1 out of 8 |
| B | Largely increasing atomic weight, but also chemical properties | 7 | 48 | 7 out of 8 |
Evaluate which method would have been more useful to scientists developing a classification of the elements.
82 exam-style questions on AQA GCSE Chemistry 1.2 The periodic table, covering 1.2.1 The periodic table, 1.2.2 Development of the periodic table, 1.2.3 Metals and non-metals, 1.2.4 Group 0, 1.2.5 Group 1, and 1.2.6 Group 7. Each one has a worked solution and a mark scheme showing where the marks go.