A student makes this claim: "Elements with 1, 2 or 3 electrons in their outer shell are metals. Elements with 4 or more electrons in their outer shell are non-metals."
The table shows some information about five elements.
| Element | Atomic number | Electrons in outer shell | Electrical conductivity of the solid | Metal or non-metal |
|---|---|---|---|---|
| hydrogen | 1 | 1 | does not conduct | non-metal |
| boron | 5 | 3 | very poor | non-metal |
| carbon (graphite) | 6 | 4 | good | non-metal |
| magnesium | 12 | 2 | good | metal |
| aluminium | 13 | 3 | good | metal |
Explain, in terms of electrons, why magnesium is classified as a metal.
Sulfur has the electronic configuration 2.8.6. Explain, in terms of electrons, why sulfur is classified as a non-metal.
Evaluate the student's claim. Use the data in the table.
Explain why solid magnesium and graphite both conduct electricity but solid sulfur does not.
50 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.