Question

Which statement is true about the elements present in a pure substance?

Answer 1

I'm not sure but I think is C or D.

Answer 2

Answer: Option (D) is the correct answer.

Explanation:

An element is defined as a substance that contains atoms of one type.

For example, a piece of sodium metal will contain only atoms of sodium.

Therefore, it is a pure substance. Whereas a compound is a substance that consists of two or more different atoms in similar composition.

For example, $CaCl_{2}$ is a compound.

When elements change into compounds then they tend to change their chemical properties.

Hence, we can conclude that the statement they can only be separated by chemical methods, is true about the elements present in a pure substance.