An atom of an unknown element XXX has the electronic configuration 2.8.18.32.8.18.32.8.18.3.
Explain how the electronic configuration of element XXX is linked to its period in the periodic table.
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.