Physical science
posted by sandy .
how can i calculate the number of: 1.molecules in 30g water.2.atoms in 50 dm^3 nitrogen gas.3.nucleons in 10 cm^3 flourine gas?

1. Hint:
One mole of water (18 grams) contains 6.022E23 molecules of H2O).
2. Hint: There are 6.022E23 molecules in 1 mole N2 which occupies 22.4 L at STP and the number of atoms is twice that.
3. Hint:How many moles F2 do you have? That will be 10cc/22,400 = ??
How many F2 molecules do you have? That will be moles x 6.022E23. How many atoms F2 do you have. You will have twice the number of molecules. How many nucleons do you have? There are 9 protons and 10 neutrons in each molecule of F2. 
Calculate the total number of ions in 2,0g K2SO4

3.13E23