Answer : The correct option is, (4) one; five
Explanation :
Lewis-dot structure : It shows the bonding between the atoms of a molecule and it also shows the unpaired electrons present in the molecule.
In the Lewis-dot structure the valance electrons are shown by 'dot'.
The representation of valence electrons of an atom by dots around the symbol of an element is said to be the Lewis-dot symbol.
In the representation of Lewis-symbol, one electron dot must put on each side of the element symbol then paired the electrons.
As per information, element A has 1 valence electron and element B has 5 valence electrons.
Thus, the valency of A is one and B is five.
