Convert amount of molecules into moles using Avogadro’s number
9.40 x 10^25 molecules H2 x 1 mole / 6.02 x 10^23 molecules
= 156 moles H2
Convert moles of H2 into grams using H2’s molar mass (1.01 x 2 = 2.02)
156 mol H2 x 2.02 g / 1 mol
= 315 g H2
B) land cools off much faster than water (creating a air region of high density above land and lower density above sea)
X is usually representing time so years, days, etc