Which of the following represents the least number of molecues?
(a)20.0 g of h2o (18.02g/mol)
(b)77.0 g of ch4 (16.06 g/mol)
(c)68.0 g of cah2 (42.09 g/mol)
(d)100.0 g of n2o (44.02 g/mol)
(e)84.0 g of hf (20.01 g/mol)

a) 20g of H2O (18.02 g/mol) molecules=6.68x10^23

Explanation:

In order to find the amount of molecules of each of the options, we need to follow the following equation.

So, let´s get the number of molecules for each of the options.

the smalest number is in option a)

Best of luck.

the answer is na (sodium)