Question

What is the valency of silicon atoms?
(a). 4
(b). 3
(c). 2
(d). 1

Answer 1

Hint: Valency of every element is related to their group number of the periodic table. Also, Carbon and Silicon atoms both have the same valency.

Complete answer:
1. First of all, the definition of Valency is “The combining capacity of an atom is known as its valency. The number of bonds that an atom can form as part of a compound is expressed by the valency of the element”
2. In more simple terms, we can say that valence electrons are those electrons which are present in the outermost orbital of the atom.
3. We can calculate the valency in the flowing way. An atom’s valence is equal to the number of electrons in the outer shell when that number is four or fewer. Then the valence in the outer shell is equal to eight minus the number of electrons. Once we are aware of the number of electrons we can calculate the valence easily.
4. We can take an example, for instance, Oxygen has six valence electrons and therefore, the valency of oxygen atom is 8-6=2
5. Therefore, Silicon has 4 outermost electrons in its valence shell which is less than 8. Therefore, the valency of silicon atoms is 4.

Additional information:
Valency is different from the oxidation number. Thus, the valency of nitrogen is 3, whereas it can have oxidation numbers from -3 to +5. The oxidation number is the hypothetical charge of an atom in a molecule or ion, and it is a measure of its apparent capacity to gain or lose electrons within that species. The importance of valency is that when two atoms react, their outer shell first comes into contact and it is therefore the outer shell electron that is normally involved in chemical reaction. The atoms exchange valence electrons in chemical reaction to stabilize their valence shell.

Note: It should be noted that loss of electron or electron gain called atom charge, Positive charge will be attained by donating an electron and negative charge vice versa. So valence has no sign, Charge has both positive and negative signs.