The Atmosphere Flashcards
What did the atmosphere consist of 4.6 billion years ago ?
Carbon dioxide, little or no oxygen and small amounts of other gases e.g. methane and ammonia
What happened to water vapour?
Volcanic activity released water vapour which condensed to form oceans. The water began dissolving gases, e.g. ammonia, creating ammonia, compounds and nitrogen containing substances. Nitrogen from volcanic activity was probably stored in the atmosphere because it is so unreactive.
What was the atmosphere like 2.7 billion years ago?
Plants and algae began to build up in oceans and there was a carbon dioxide decrease in the atmosphere. Carbon dioxide was being used during photosynthesis. Oxygen was released from the plants and entered the atmosphere in a process called photosynthesis.
What is the equation for photosynthesis?
Carbon dioxide + water => glucose + oxygen
What enabled animals to evolve?
Oxygen being present in the atmosphere enabled animals to evolve putting carbon dioxide back into the air.
Glucose + oxygen => carbon dioxide + water
Properties and uses of oxygen
This is the gas we need to say life. It is also needed for burning. A burning splint will burn brightly in this gas.
Properties and uses of nitrogen
This gas makes up most of the air. It does not react very much.
Properties and uses of argon
This gas does not react at all. It is used in lightbulbs so that the metal in the lightbulb can get very hot without burning.
Properties and uses of helium
This gas is very light, so we use it in balloons. It does not react with anything at all. Divers use this gas.
Properties and uses of carbon dioxide
This gas is in the air we breathe out. It is used in fire extinguisher. It turns limewater milky.
Properties and uses of methane
This is the gas in the gas taps. It comes from under the north sea. It burns with a blue flame if there is plenty of air.
Properties and uses of nitrogen dioxide
This is a brown gas with a strong smell. It is poisonous. It can cause acid rain.
Properties and uses of hydrogen
This gas is very light and very reactive. A test tube of this gas will burn with the squeaky pop when a lit splint is held to the mouth of the test tube.
