Atmosphere And Oxygen Y8 Flashcards
What was the Earths atmosphere mostly made of 4.5 billion years ago?
Water vapour
What were the gases in the atmosphere 4.5 billion years ago?
Water vapour, carbon dioxide and nitrogen
What was the temperature 4.5 billion years ago?
Really hot with lots of volcanoes- so hot most water gets turned into water vapour
What was the earths atmosphere mostly made up of 4 billion years ago?
Carbon dioxide
What was the temperature 4 billion years ago?
Earth cooled- water vapour condensed creating oceans
Gases in atmosphere 4 billion years ago?
Carbon dioxide, water vapour, nitrogen, ammonia and methane
What happened to the atmosphere 2.5 billion years ago?
Increased in oxygen ,decreased in carbon dioxide
What caused the changes 2.5 billion years ago?
Evolution of photosynthesising
Bacteria and algae
What was the atmosphere mostly made of 200million years ago?
Atmosphere mostly nitrogen and oxygen
What caused the changes in the atmosphere 200 million years ago?
Evolution of photosynthesising
Evolution of respiring animals
What is our atmosphere now like?
Atmosphere has stayed the same since 200 million years ago
Percentage of nitrogen in the atmosphere?
78%
Percentage of oxygen in atmosphere?
21%
Percentage of argon in atmosphere?
0.9%
Percentage of carbon dioxide in the atmosphere?
0.04%
Why is the composition of the atmosphere currently relatively stable?
Photosynthesising plants, absorbs, CO2 and release oxygen, respiring animals and plants absorb oxygen and release CO2. Therefore CO2 and oxygen levels remain fairly stable.
What force keeps the Earths atmosphere in place?
Gravity
How does the oxygen and phosphorus experiment work?
The phosphorus is placed in an evaporating dish inside Bell jar, which is partially filled with water. The oxygen in the air will react with the phosphorus to form a new product. The water level rises to replace the space where the oxygen was. Water rises by 21%, which is the amount of oxygen there was..
What’s the word equation for the phosphorus experiment?
Oxygen+ phosphorus—> phosphorus oxide
How does fractional distillation work to separate air?
- Call the air down to -200 degrees Celsius. Carbon Dioxide is solid at -200°C so it can be easily removed.
- Pass the liquid into the fraction column., nitrogen has a boiling point of -196°C so it turns from liquid to gas and rises at the column and is collected at the top.
Oxygen has a boiling point of -183°C, so it stays as a liquid at the bottom of the column and can be collected there .
The column is cooler at the top and warm at the bottom
At what temperature does air turn from gas to liquid?
-200°C
What is the name given when a gas turns to a liquid?
Condensing
What gas is removed from the top of the fractionating column when liquefied air is distilled.
Nitrogen
What is the property and use for nitrogen?
Important plant nutrient and is used to make fertilisers
What is the property and use for oxygen?
Reactant in respiration, life support and other medical uses
What is the property and use for carbon dioxide?
Starves fire of oxygen and is used in fire extinguishers
What is the property and use of helium?
It weighs less than air and is used to fill balloons
What is the property and use of neon?
It glows and is used in advertising signs
What is the property and use of argon?
Inert(unreactive) and used to fill lightbulbs
What is the copper experiment?
1.There is powdered copper in the tube. The mass of the tube was measured then the tube is heated..
2. the syringes either side was passed over copper while it was being heated.
Each time the syringes passed over the less volume of gas there was.
In the copper experiment, what happened to the copper?
The pink brown copper turned black
What happened to the mass of the copper in the copper experiment?
Increased in mass, because copper oxide was formed
Why does the copper experiment tell us how much oxygen there is in the air?
All the oxygen will react with the warm copper to form copper oxide. Therefore 79% of gas should left in the syringe as 21% has reacted with the copper.
What is formed when an element burns in oxygen?
Oxide
What is the type of reaction called when an element burns an oxygen?
Oxidation because the element is gaining oxygen
What are non-metal oxides?
They are acidic and exist as gases.
What is a metal oxide?
Alkalines that exist as solids
What are the three things in the fire triangle?
Heat, oxygen and fuel
What happens when you remove one of the three things on fire triangle?
The fire will go out
What are the three types of fire extinguishers?
- Powder-contains the powder which smothers fire.(removing oxygen.)
- Carbon dioxide.-used for fires involving electrical apparatus.
- Water.-suitable for burning solids. 
What is combustion?
Burning in oxygen(releases, heat energy)
What is oxidation?
Reaction with oxygen, where a substance gain some oxygen
What is incomplete combustion?
When you burn something with a limited supply or insufficient oxygen
A candle burns, what’s the chemical reaction
Oxygen+ candle wax—> water+ carbon dioxide(+ heat/energy)
What is released in incomplete combustion?
Carbon monoxide or just carbon
What is released in combustion?
Carbon dioxide
How to test for carbon dioxide gas?
If you put it in lime water, the lime water will turn cloudy.
How to test for water?
Blue cobalt, chloride paper will turn pink in the presence of water
Is carbon monoxide poisonous?
Yes, it binds to haemoglobin in red blood cells, preventing oxygen from getting to your vital organs
What happens to the weight of a metal when it is burnt?
Increases
