Look at the elements formula search it up
Answer: 121.43 Moles
Explanation: A mole of any element or compound is equal to 6.02 x 10^23 atoms/molecules
The fact that it’s methane doesn’t even matter, all you need is the number of atoms.
So you take 7.31 x 10^25 / 6.02 x 10^23 which equals 121.43 moles.
Talc is not a good choice when building a statue because the mineral Talc is one of the weakest minerals on the Mohs Scale with a hardness of 1 since it could be scratched by a fingernail, which means that when people build a statue with Talc, it could be easily broken down.
If one starts with 0.020 g of Mg, 0.0008 moles of H2 would be made if the reaction is complete.
Going by the balanced equation of reaction in the image, 1 mole of Mg will produce 1 mole of H2 in a complete reaction.
If 0.020 g of Mg is started with:
mole of Mg = mass/molar mass
= 0.020/24.3
= 0.0008 moles
Since the mole of Mg to H2 is 1:1, thus, 0.0008 moles of H2 will also be made from the reaction.
More on stoichiometry can be found here: brainly.com/question/9743981