Author Question: Which contains more moles of material: 80 grams of helium gas (He, having atomic weight 4.0 g/mol) ... (Read 95 times)

c0205847 · **on:** Jul 29, 2018

Which contains more moles of material: 80 grams of helium gas (He, having atomic weight 4.0 g/mol) or 400 grams of argon gas (Ar, having atomic weight 40 g/mol)?

A) helium
B) argon
C) Both contain the same number of moles.

Question 2

When a vapor condenses,

A) the temperature of the substance increases.
B) the temperature of the substance decreases.
C) heat energy leaves the substance.
D) heat energy enters the substance.