A student makes three statements about electronic configurations of the first 20 elements.
Statement 1: every element in Group 0 has 8 electrons in the outer shell of its atoms
Statement 2: the number of occupied shells in an atom is equal to the period number of the element
Statement 3: for elements in Groups 1 to 7, the group number is equal to the number of outer-shell electrons
Which statements are correct?
2 and 3 only
2 only
1 and 3 only
1, 2 and 3
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.