Science homework help!?

Question

Say you have 8 N2 molecules and 2 O2 molecules in a batch of dry air.

1)What is the mass of this air?

2) 8 times atomic weight of nitrgen=8 X___=____

2 times atomic weight of
oxygen = 2 X ____=_____
Total_____

Answer 1

atomic weight of N is 14
atomic weight of 0 is 16

i think that's a start