Question

State, whether the following statements are true or false:
(i) Fluorine has higher electron affinity than chlorine.
(ii) Similar electronic configuration is repeated after intervals of 2, 8, 8, 18 and 32.
(iii) Al₂O₃ is an amphoteric oxide.
(iv) On moving horizontally across a period, number of valency electrons increases from one to eight.
(v) All members of zero group are non-metals.
(vi) The elements with higher electron affinity have higher ionization potential.

Answer 1

(i) False
Due to small size of fluorine, incoming electron faces inter-electronic repulsion. Hence, electron affinity of flourine is lower than that of chlorine.

(ii) True
The elements with similar properties recur only after intervals 2, 8, 18, 18 or 32 because electronic configurations with similar valence shell configuration are repeated only after either of these intervals.

(iii) True
Al₂O₃ can react with both acids and alkalis; hence, it is an amphoteric oxide.
Al₂O₃ + 6H⁺ → 2Al³⁺+ 3H₂O
${\mathrm{Al}}_2{\mathrm{O}}_3+2{\mathrm{OH}}^{-}+3{\mathrm{H}}_2\mathrm{O}\to 2\mathrm{Al}{\left(\mathrm{OH}\right)}_4^{-}$

(iv) True
As we move towards right in a periodic table, electrons are added in common valence shell of atoms.

(v) True
Zero group elements have completely filled valence shell; so, they cannot lose electron. Hence, they are non-metallic in nature.

(vi) True
An atom with high electron affinity releases large amount of energy when it gains an electron for completing its valence shell. So, it will need high amount of energy to lose electrons; i.e., it will have higher ionisation potential.