Question

Number of electrons in the valence orbital of nitrogen in an ammonia molecule are
A) 8
B) 5
C) 6
D) 7

Answer 1

Hint: We know that an atom has many shells where the electrons are present. The shells are named as K, L, M, N etc. And the outermost shell of atoms is named as valence shell. And the electrons in the valence shell are named as valence electrons.

Complete step by step solution:Let's discuss how to count the valence electrons present in an atom. For that, we must know the atomic number of the atom. Let's understand with the help of an example. Oxygen atom has an atomic number of 8. So, its electronic configuration is 2,6. So, the outer shell has six electrons.
Similarly, we have to calculate the electrons of the valence shell of the nitrogen atom. A Nitrogen atom has the atomic number of 7. So, the configuration of nitrogen atoms is 2,5. So, we find that five electrons are present in the valence orbital of nitrogen atoms.
Let's discuss the ammonia molecule in detail. Ammonia has the formula of . The N atom has five numbers of valence electrons and three hydrogens have one hydrogen atom each. Nitrogen atom shares three numbers of electrons with three atoms of hydrogen and completes its octet. Therefore, three covalent bonds formed and one electron pair remain as lone pairs.

Hence, the valence orbit of the nitrogen atom has five numbers of valence electrons.

Hence, option B is right

Note: Always remember that, a covalent bond is formed because of the share of electrons between them. The electrons when shared help to achieve octet and stabilize the compound. The electrons that do not take part in the bond formation are lone pairs.