The densities of some group 1 metals are shown. Water has a density of 1.00 g cm−3\mathrm{g\,cm^{-3}}gcm−3.
| Metal | Li | Na | K | Rb |
|---|---|---|---|---|
| Density / g cm−3\mathrm{g\,cm^{-3}}gcm−3 | 0.53 | 0.97 | 0.86 | 1.53 |
A small piece of rubidium is added to a large trough of water containing universal indicator. What is observed?
It floats, melts into a ball and fizzes; the indicator turns purple
It floats and reacts explosively; the indicator turns red
It sinks and reacts more slowly than potassium; the indicator turns purple
It sinks and reacts explosively; the indicator turns purple
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.