Question

A compound is a ……. substance made up of ……….

Answer 1

Hint: Pure substance has fixed composition. It has been classified into elements and compounds. Element contains only one type of atom while compound contains two or more different types of atoms.

Complete answer:
Pure substance has fixed composition and is classified into two categories i.e. element and compound. An element contains one type of atom or molecule. For example copper, gold, silver, hydrogen gas and oxygen gas. On the other hand, compounds contain two or more different types of elements. For example water \[({{H}_{2}}O)\] is made up of two different types of elements i.e. hydrogen and oxygen. Similarly, Glucose \[({{C}_{6}}{{H}_{12}}{{O}_{6}})\] consists three different types of elements i.e. carbon, hydrogen and oxygen. It is worth mentioning that different types of atoms are present in a compound in a definite and fixed ratio and cannot be separated into constituents atoms by simple physical methods. However, they can be separated into constituent atoms by chemical methods.
 Therefore, a compound is a pure substance made up of two or more atoms of different elements.

Additional Information:
Compounds have different properties than the properties of constituent elements. Let us consider the example of water which is made up of hydrogen and oxygen gas. Water and oxygen gas have different properties such as water being used as a fire extinguisher while oxygen gas is a supporter of fire. Similarly, water is a liquid while oxygen is a gas i.e exist in different physical states.

Note:
It is important to note that a compound is a pure substance made up of two or more atoms of different elements. In a compound, different types of atoms are present in a definite and fixed ratio. They cannot be separated into constituent atoms by simple physical methods.