David has a weather balloon that he fills with helium and then releases. As the balloon rises into the atmosphere, the balloon gets bigger and bigger. Why?
A) the temperature of the gas is decreasing, so the volume is increasing
B)the volume is increasing as the pressure inside is decreasing to match the air pressure outside the balloon
C)gas is leaking out of the balloon, so there isn't as much volume
D)this doesn't happen -- the balloon will actually stay the same size

B

Explanation: since the balloon is getting bigger it would make sense for the volume to increase ( get bigger) when volume increases the pressure decreases

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.