kinetic theory??

Question

1.balculate the rms speeds at 20℃ of atoms of:(A)helium (4u);(B)neon (20u);(C)radon (222u).

2.the temperature in the intreior of the sun is about 2 ＊(10^7) K.what is (A)the average kinetic energy,and(B)the rms speed of protons?

Answer 1

1) Using the formula:
crms = √(3kT/m) where
k = Boltzmann's constant
T = Absolute temperature
m = Mass of the particle
So crms of helium atoms = √(3 × 1.38 × 10-23 × 293/4 × 1.66 × 10-27)
= 1352 m/s
crms of neon atoms = √(3 × 1.38 × 10-23 × 293/20 × 1.66 × 10-27)
= 604 m/s
crms of helium atoms = √(3 × 1.38 × 10-23 × 293/222 × 1.66 × 10-27)
= 181 m/s
2) Mass of proton = 1u. So
Average kinetic energy = (3/2)kT
= (3/2) × 1.38 × 10-23 × 2 × 107
= 4.412 × 10-16 J
crms of a protons = √(3 × 1.38 × 10-23 × 2 × 107 /1.66 × 10-27)
= 7.063 × 105 m/s

Answer 2

you can refer to your another post on [kinetic interpretation of pressure]