During a laboratory demonstration, a teacher adds small, equal-sized pieces of lithium and sodium separately to troughs of water. The teacher notes that sodium reacts far more vigorously than lithium, melting into a ball and moving rapidly across the water's surface, whereas lithium reacts more slowly without melting.
The electronic configurations of lithium and sodium are:
Both elements react by losing their outer-shell electron to form 1+1+1+ ions.
Explain, in terms of their electronic configurations, why sodium is more reactive than lithium.
75 exam-style questions on Edexcel GCSE Chemistry 7.1 Group 1, covering 7.1.1 Classifying elements by group in the periodic table and 7.1.2 Properties and reactions of the alkali metals. Each one has a worked solution and a mark scheme showing where the marks go.