In which location would the air most likely be at standard temperature and pressure?

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.

If a gas has an initial pressure of 101kpa and a volume of 10l, then it expands to a volume of 20l, what is the new pressure?

What is a difference between a mixture of elements and a mixture of compounds