Which process involves mass movement within a substance?
a. conduction
b. convection
c. radiation
d. reflection

Which statement accurately describes the relationship between air pressure, air density, or altitude? as altitude increases, pressure increases.as altitude increases, air density increases.air pressure and density are lowest at sea level.denser air exerts more pressure than less dense air.

What happens to the average kinetic energy of a gas when the particles of the gas collide against each other at a constant temperature and volume? explain your answer.

Estimate the molar mass of the gas that effuses at 1.6 times the effusion rate of carbon dioxide.