Question

choose from the following elements with atomic number are given in parentheses H1 h e to see 689 and a 11 CL 12 MG 12 . A) smallest element of the third period .
B) a novel gas.
C) a metal of third period having valence D) 1. most non metallic element of second period .

Answer 1

a)sodium (argon also ) b) argon d)fluorine

Answer 2

Hii dear,

● Answer -
A) Smallest element of the third period => Cl (17)
Because atomic radius decreases from left to right in a period.

B) A noble gas => He (2)
Noble gases are He, Ne, Ar, Xe, Kr

C) A metal of third period having valence 1 => Na (11)
Because group 1 elements have valency 1.

D) Most non metallic element of second period => F (9)
Because F is highly electronegative (electrophilic).



Hope this helped...