Three elements A, B and C have 3,4 and 2 electrons respectively in their outermost shell. Give the group number to which they belong in the modern periodic table. Also, give their valencies.

Explanation

The electrons present in the outermost shell are also known as valence electrons The desired information is given :
`{:("Element","Valence electrons","Group No.","Valency",),(" A"," 3"," 13"," 3",),(" B"," 4"," 14"," 4",),(" C"," 2"," 2"," 2",):}`