有10,0g的C2H5OH,含有1.31 x 1023（二十三次方）个分子,此物质中有多少个H原子?
A 10.0 g sample of C2H5OH contains 1.31 x 1023（二十三次方） molecules.How many atoms of H does it contain?
a.1.31 x 1023
b.2 x 1.31 x 1023
c.5 x 1.31 x 1023 See pp.50-53
d.6 x 1.31 x 1023 ÷ 2