Define valency by taking examples of nitrogen and boron.

1.	Define valency by taking examples of nitrogen and boron.
Answer» Valency: The number of electrons present in outer most orbit of an atom is called its valency. Valency of Nitrogen : a) Atomic number of nitrogen is 7. b) The distribution of electrons is 2, 5. c) The outer most orbit has 5 electrons. d) Hence its valency should be 5. But it is easier to nitrogen to gain 3 electrons than to loose 5 electrons for becoming octet. e) Hence the valency of nitrogen is ‘3’. Valency of Boron : a) Atomic number of boron is 5. b) The distribution of electrons is 2, 3. c) The outer most orbit has 3 electrons. d) Hence the valency of boron is 3.

Answer»

Valency:

The number of electrons present in outer most orbit of an atom is called its valency.

Valency of Nitrogen :

a) Atomic number of nitrogen is 7.

b) The distribution of electrons is 2, 5.

c) The outer most orbit has 5 electrons.

d) Hence its valency should be 5. But it is easier to nitrogen to gain 3 electrons than to loose 5 electrons for becoming octet.

e) Hence the valency of nitrogen is ‘3’.

Valency of Boron :

a) Atomic number of boron is 5.

b) The distribution of electrons is 2, 3.

c) The outer most orbit has 3 electrons.

d) Hence the valency of boron is 3.

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