Question

Question #2065a

Answer 1

The ease of losing and gaining valence electrons with regards to their atomic radius too.

Explanation:

1. Generally, for Grp l metals, their reactivity increases down the grp. All grp l metals have one valence electron and only need to lose one electron to achieve a noble gas electronic configuration.
   Down the grp, the atomic radius increases and hence, the attraction between the positive nucleus and the negative valence electron becomes weaker. In this way, the valence electron is lost very easily and reactivity is high.

2. On the other hand, for non-metals such as those in grp Vll, the halogens have 7 valence electrons and will need to gain one electron instead to achieve a noble gas electronic configuration.
   Down the group, the atomic radius increases and the attraction between the positive nucleus and the valence electrons gets weaker. Therefore, it becomes harder to gain that one electron down the grp and so reactivity decreases down the grp.