An element A has 2 electrons in its fourth shell. State:

(a) its atomic number

(b) its electronic configuration

(c) its valency

(d) position in the periodic table

(e) is it a metal or a non-metal?

(f) is it an oxidising or reducing agent?

(a) Atomic number is 20.

(b) Its electronic configuration is 2, 8, 8, 2.

(c) +2, as the element tries to donate the two valence electrons, gain a stable octet configuration and become an electropositive ion.

(d) Group 2 Period 4

(e) Metal, as the element has 2 valence electrons and tries to donate it to attain a stable configuration.

(f) Reducing agent, as metals are strong reducing agents.