Avogadro's number: a Is constant irrespective of the mass of the gases b Varies according to the mass of the gases c Varies according to the pressure on the gases d All of the above

Avogadro's number, which is approximately \(6.022 \times 10^{23}\), is a fundamental constant that represents the number of atoms, molecules, or particles in one mole of a substance. Let's analyze the options: a. **Is constant irrespective of the mass of the gases**: This statement is true. Avogadro's number is a constant and does not change with the mass of the gas. b. **Varies according to the mass of the gases**: This statement is false. Avogadro's number does not vary with the mass of the gas. c. **Varies according to the pressure on the gases**: This statement is also false. Avogadro's number is a constant and does not change with pressure. d. **All of the above**: Since options b and c are false, this statement is also false. Based on this analysis, the correct answer is: **a. Is constant irrespective of the mass of the gases.**