The elements Be, Mg and Ca each having two electrons in their outermost shells are in periods 2, 3, and 4 respectively of the modem periodic table. Answer the following questions, giving justification in each case:
(i) Write the group to which these elements belong.
(ii) Name the least reactive element.
(iii) Name the element having largest atomic radius.
(i) Group 2. Since, they have 2 valence electrons.
(ii) Be is the least reactive because of smaller atomic size.
(iii) Ca possess larger atomic size, when we move from top to bottom in a group, atomic radius increases due to addition of new shell.