One mole of CH4 contains:
Methane gas is a gas whose formula is CH4 that contains 1 mole of carbon and 2 moles of hydrogen.
As we know that 12 grams of pure carbon powder is equal to 1 mole. The number of carbon atoms present in this 1 mole is known as Avogadro’s number which is a constant whose value is 6.023×1023.
According to the formula, 2 moles of Hydrogen is 2 times the relative molecular mass of Hydrogen which is 4 g. So, 1 mole of CH4 contains 4 g atoms of hydrogen.
Thus, option A is correct.