1Kinetic Theory (3); II Law of Thermodynamics(2)?

Question

Calculate the number of molecules in m= 29 g of a substance , molar mass M= 63 g/mol. Express your result in scientific notation with 3 sig. fig. i.e. x.yzEw

Answer 1

By definition, a mole contains a constant number of molecules.

http://en.wikipedia.org/wiki/Mole_(unit)

You know the fraction of a mole that you want so you can compute the number of molecules.

You know what scientific notation is.

So what's the problem?