The elements 4Be, 12Mg and 20Ca, each having two valence electrons in their valence shells, are in periods 2, 3 and 4 respectively of the Modern Periodic Table. Answer the following questions associated with these elements, giving reason in each case:
- In which group should they be?
- Which one of them is least reactive?
- Which one of them has the largest atomic size?
- In group 2, as each element has two valence electrons.
- Be is least reactive because Be has the least tendency to lose electrons.
- Ca has the largest atomic size as Ca has the maximum number of shells and atomic size increases down the group