Rubidium and caesium are both elements in Group I of the Periodic Table. Which comparison between rubidium and caesium is correct?
- ACaesium has the higher density and the greater reactivity.
- BCaesium has the higher density; rubidium has the greater reactivity.
- CRubidium has the higher density and the greater reactivity.
- DRubidium has the higher density; caesium has the greater reactivity.