Most Probable Speed - Atoms From An Oven
I'm looking to find the most probable speed of atoms ejected from an oven.
Temp (T) is 900°C (so 1173.15K).
The material is aluminium with molar mass 0.027kg mol-1
I've got the formula vmp=√(2kT/m)
I'm fine with everything above, but I'm not sure what value to use as the Boltzmann constant k.
Can anyone please help me here? Do I have the right equation and what value for the constant should I use (sounds silly, but it changes depending upon units. I've tried a couple but get silly tiny speeds out. I think I should expect something in the region of a few hundred metres per second).