In the following structure where A and B represent two different elements, the valency of A is and B is . Element B is centered, with two electron dots above, one to each side, and one below. On the left and right of B are atoms of A, each with one electron dot between A and B. Below is an atom of A, with an electron dot above it, also between A and B. Group of answer choices

1. one; three
2. eight; eight
3. three; five
4. one; five

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.