Question

Which of the following is an element?
(A)S
(B)$S{{O}_{2}}$
(C) $C{{O}_{2}}$
(D) None of the above.

Answer 1

Hint: Elements are the pure substances that are made up of only one type of atom whereas compounds are the substances composed of molecules or different atoms in certain ratios held by covalent or ionic bonds.

Complete answer: Let us first understand the major differences between element and compound and then categorize the above given options as follows:-

- Elements are pure substances which are composed of only one type of atom whereas compounds are substances which are formed by two or more different types of elements that are held together chemically in fixed proportions.
- There are nearly 118 elements at present (out of which nearly 94 elements occur naturally on Earth) whereas compounds are almost countless.
- Elements are classified as metals, nonmetals and metalloids whereas compounds are classified according to their bonds which can be ionic, covalent or metallic bonds.
-S: It represents Sulphur and has only one atom. Therefore, it is an element.
-$S{{O}_{2}}$ : It represents Sulphur dioxide and it consists of 2 atoms that are sulphur (S) and oxygen (O). Therefore, it is a compound.
-$C{{O}_{2}}$ : It represents Carbon dioxide and it consists of 2 atoms that are carbon (c) and oxygen (O). Therefore, it is a compound.
From this, we conclude that S is an element whereas $S{{O}_{2}}$ and $C{{O}_{2}}$ are compounds.

Hence, the right option is (A).

Note: -Remember that the properties of elements are different from the compounds they make. For example: both hydrogen and oxygen are combustible in nature whereas the water (compound formed by hydrogen and oxygen) is not combustible. Both hydrogen and oxygen are gases whereas water is present in liquid state.