Calculate the pressures, P, in atmospheres at which the mean free path, l, of a hydrogen molecule will be 5.00 μm, 5.00 mm, and 5.00 m at 20.0 °C. The diameter of a H2 molecule is 270 pm.

Americium-241 undergoes fission to produce three neutrons per fission event. if a neutron-absorbing material is mixed in with this sample so that the rate of neutron production drops down to 1.8 neutrons per fission event, which will be effective at achieving a critical mass? check all that apply. remove a deflective shield surrounding the sample. remove absorbent material mixed in with the sample. compress the sample of americium-241.

Which change to the system wood cause the freely-moving piston to lower?

For the reaction i2(g)+br2(g)←−→2ibr(g), kc=280 at 150 ∘c. suppose that 0.450 mol ibr in a 2.00-l flask is allowed to reach equilibrium at 150 ∘c. what is the equilibrium concentration of 2ibr, i2, br2