43 a sample of helium gas is in a sealed, rigid container. what occurs as the temperature of the sample is increased? (1) the mass of the sample decreases.
(2) the number of moles of gas increases.
(3) the volume of each atom decreases.
(4) the frequency of collisions between atoms increases.

1. 1 mole of anything contains 6.022x10^23 pieces  

d  

2. a  

3. c, number  

5. 1.24x10^24atoms / 6.022x10^23atoms/mole = 2moles h2 atoms  

6. fe2br3 mass = 2moles x mass fe + 3 moles x mass br  

molar mass = grams / number of moles = g/mole  

to find moles = g / molar mass  

to find mass = g = molar mass / moles