Which statement is true about the elements present in a pure substance? a they maintain their chemical properties. b they are composed of many compounds. c they can be separated by physical methods. d they can only be separated by chemical methods.

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, 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.

i believe it is 40–40–20%

explanation: