What do you call the water vapour in the atmosphere?

Why does air cool down the higher up you go when we're getting closer to the sun? What is the name of the Roman Goddess which is named after a planet? How much did Apollo 13 shuttle cost? How long would it take a person to walk around the earth? What should you do for a hot air balloon science project? How many flags on the moon? What are some common colors of laser pointers? Did cosmonauts ever fly with astronauts? Were there any survivors of the space shuttle challenger? Are white dwarfs older than the sun? What were the moon missions by man? How do you get Giratina on Pokémon Mystery Dungeon Explorers of Darkness? When was 'Mary Celeste' first spotted? How does the compass help people? What does chromasphere means? How do you train at zero gravity for space? What is the history of the quote it is during your darkest moments when you must focus to see the light? The competition between the US and the USSR to put a man on the moon was called the? What is the name for the sun all of the planets and the comets etc that revolve around it? What are facts about the altocumulus cloud?

What do you call the water vapour in the atmosphere?