An element Z Z\,Z forms a stable monoatomic ion Z2−Z^{2-}Z2− that has the same ground-state electronic configuration as a krypton atom. Which of the following elements is in the same group of the periodic table as ZZZ?
Iodine
Barium
Tellurium
Phosphorus
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.