The atomic weight of carbon (C) is 12 and hydrogen (H) is 1. What is thepercentage of hydrogen in CH4?

To calculate the percentage of hydrogen in CH4, follow these steps:

1. Calculate the molar mass of CH4. The molar mass of a molecule is the sum of the atomic weights of all the atoms in the molecule. For CH4, the molar mass is 12 (for one carbon atom) + 1*4 (for four hydrogen atoms) = 16 g/mol.

2. Calculate the total mass contributed by hydrogen. In CH4, there are four hydrogen atoms, each with an atomic weight of 1, so the total mass contributed by hydrogen is 1*4 = 4 g/mol.

3. Calculate the percentage of the total mass that is contributed by hydrogen. The formula for this is (mass of hydrogen / total mass) * 100%. So, (4 g/mol / 16 g/mol) * 100% = 25%.

So, the percentage of hydrogen in CH4 is 25%.