Question

The symbol of carbon:
(A) C
(B) Cr
(C) Ca
(D) Co

Answer 1

Hint: Usually we use either the first alphabet or first two alphabets from the name of the element to write its chemical symbol. Sometimes two alphabets chosen from the name need not be the first two alphabets. They can be any alphabet from the name.

Complete step by step answer:
> Cr is the symbol of chromium. You can obtain the symbol by taking the first and third alphabet from the name chromium.
> Ca is the symbol of calcium. You can obtain the symbol by obtaining the first two alphabets from the name calcium.
> Co is the symbol of cobalt. You can obtain the symbol by obtaining the first two alphabets from the name cobalt.
The symbol of carbon is C. You can obtain the symbol by obtaining the first alphabet from the name carbon.
The atomic number of carbon is 6. Its electronic configuration is $$1s^{2}2s^{2}2p^2$$. Carbon atom has 4 electrons in its outermost shell and needs 4 more electrons to complete its valence shell and attain stable electronic configuration of nearest noble gas neon. For this purpose, a carbon atom shares 4 electrons with 4 other atoms to form four sigma covalent bonds. Thus, carbon is a tetravalent element.

Hence, the option (A) represents the correct option.

Note: The chemical symbols of hydrogen and helium are H and He respectively.
These are obtained when you use either the first alphabet or first two alphabets from the name of the element to write its chemical symbol.