Question

Example of an element is:
(A) Water
(B) Sodium hydroxide
(C) Hydrogen
(D) Sugar

Answer 1

Hint: We need to know what an element is. In chemistry, an element is a pure substance which consists of a single type of atom and cannot be broken down to simpler substances .An element can be changed from one form to another. We have to remember that the element present in particles has only one type of atom. An atom is in turn made up of protons, neutrons and electrons.

Complete step by step answer:
We have to remember that each element has its unique atomic number which is the number of protons in its atomic nucleus. Elements combine to form molecules.
In order to classify a substance as an element or a molecule, we must understand its composition. Let us have a look at each of the given substances one by one.
(A) Water: Water is made up of Hydrogen and Oxygen (\[{H_2}O\]). Here, two different types of atoms are present. Hence it cannot be considered as an Element. Therefore, the option A is incorrect.
(B) Sodium hydroxide: Sodium hydroxide has the molecular formula as\[NaOH\]. It is clear that it is made up of two 3 types of atoms, that is Sodium (\[Na\]), Oxygen (\[O\]) and Hydrogen (\[H\]). Hence it is not an element. Therefore, the option B is incorrect.
(C) Hydrogen: Hydrogen is the chemical element with the symbol \[H\] and atomic number \[1\]. It has no other type of atoms associated with it.Hence it is an element. Therefore, the option C is correct.
(D) Sugar: Sugar is a type of soluble carbohydrate with molecular formula as \[{C_{12}}{H_{22}}{O_{11}}\]. Clearly, there are different kinds of atoms present hence it is not an element. Therefore, the option D is incorrect.

So, the correct answer is Option C.

Note: It must be noted that the properties of a molecule or a compound is different from those of its constituent elements. For example, Hydrogen and oxygen are individually elements and are gases but their combination is a liquid, i.e. water. Also the individual elements of a molecule can be separated by chemical methods and not physically.