Question

1] fluorine is more reactive than chlorine .Why ?

2] Mg is more metallic than be .why ?

Answer 1

1) The electron affinity of fluorine is less than chlorine.Still it is more reactive than chlorine due to following reasons:

i) The low dissociation energy of F2 molecule and high hydration energy of F- ion more than compensates for the low electron affinity of fluorine.The oxidizing power of flourine is more than chlorine.

ii) The electronegativity of fluorine is more than chlorine.

2) Metallic character is the tendency of an atom to loose electrons.On moving down the group, the atomic size increases due to which the ionization energy decreases and thus the ability to loose electron increases.Therefore , Mg is more metallic than Be.