is the following sentence true or false?

Question

To determine the number of representative particles in a compound, you count the molecules by viewing them under a microscope.__true______

Most molecules are too small to see with an ordinary microscope.

Can molar masses be calculated directly from atomic masses expressed in grams.

yes.
Atomic masses of
C= 12
O = 16
molar mass of
CO2 = 12 + (2x16) = 12 + 32 = 44 g/mol.