C6H15, C2H5 has a molar mass of 29g/mol. 87 divided by 29 is 3. Then multiply each element subscript by 3
Answer:
1,000 - 2,000
Explanation:
Just look at the bar graph. The bar ends at about 1,500 which is between 1,000 - 2,000. That is the only valid answer for this problem.
Answer: Number of molecules of hydrogen gas 
Explanation:

Number of moles of sodium =
According to reaction , 2 moles of sodium produces 1 mole of hydrogen gas , then 2.11 mol of sodium will=
of hydrogen gas that is 1.05 moles of hydrogen gas.
Number of molecules =
moles of substance
Moles of hydrogen gas formed = 1.05 moles
Number of molecules of hydrogen gas =
moles of hydrogen gas
Number of molecules of hydrogen gas 
I'm not writing random things to reach the 20 character requirement so I can tell you that Magnesium has the least amount of atoms.
3rd one sorry if it’s wrong