Amixture of h2 and n2 has a density of 0.216 at 300k and 500 torr. what is the mole fraction composition of the mixture

We know that:
number of moles (n) = mass / molar mass

Now, from the general law of gases:
PV = nRT
where:
P is the pressure = 500 torr = 0.65 atm
V is the volume
n is the number of moles
R is the gas constant = 0.082
T is the temperature = 300 k
We will just rearrange this equation as follows:
P = nRT / V
Then we will substitute n with its equivalent equation mentioned at the beginning:
P = (mass x R x T) / (volume x molar mass) > equation I
Now, we know that:
density = mass / volume
We will substitute (mass/volume) in equation I with density as follows:
P = (density x R x T) / molar mass 
Rearrange this equation to get the mass as follows:
molar mass = dRT/P = (0.216 x 0.082 x 300) / 0.65 = 8.4738 grams

From the periodic table:
molecular mass of hydrogen = 1 grams
molecular mass of nitrogen = 14 grams
Therefore:
molar mass of hydrogen = 2 x 1 = 2 grams
molar mass of nitrogen = 2 x 14 = 28 grams

We can assume that the number of moles of of each element is y.
We can thus build up the following equation:
2y + 28y = 8.4738
30y = 8.4738
y = 0.28246

Therefore:
mole fraction of hydrogen = 2 x 0.28246 = 0.56492
mole fraction of nitrogen = 28 x 0.28246 = 7.90888

Okay well gravitational energy is matter forced by gravity making energy though the kinetic energy then the electric energy produces electricity from the kinetic energy and the kinetic energy gets its energy from the gravitational energy. was that the answer you wanted or something else?