Topic 1&2 Flashcards
Explain why today’s atmosphere is different from the earths early atmosphere
Today’s atmosphere has a higher percentage of oxygen due to plants photosynthesising
A high percentage of nitrogen compared to the early atmosphere having carbon dioxide
The carbon dioxide levels are now only 0.04% compared to the very early atmosphere having the highest percentage of it, this has however risen due to fossil fuels being burnt
How were the oceans formed
The oceans were formed by water vapour which was another main form of atmosphere condensed
List three ways in which human activity is changing the atmosphere
Deforestation - leaving more carbon dioxide in the atmosphere
More people - taking in more oxygen and releasing more carbon dioxide
Burning more fossil fuels - release more CO2
Name the two main gases that make up the atmosphere today
Nitrogen and oxygen
What else is changing the atmosphere other than humans
Plants photosynthesising
Volcanic activity releasing sulphur dioxide and carbon dioxide
Describe how you would investigate the proportion of oxygen in the air
Pipet of air with copper in the middle
When heated, the copper will react with the oxygen to form copper oxide
This will remove the oxygen from the original measurement of gas
Therefore whatever it has decreased by is how much oxygen was in the tube
Name the three types of rock
Sedimentary
Metamorphic
Igneous
What type of rock is marble and how is it formed
Marble is metamorphic
It is formed when sedimentary rock such as chalk or limestone undergo intense heat and pressure which compacts the layers together
What type of rock is chalk
Sedimentary
Describe the difference in the way the crystals of extrusive and intrusive rock forms
Intrusive rocks have big crystals due to a slow process of cooling under the earths surface
Extrusive rocks have small crystals due to a fast process of cooling about the earths surface
Name three building materials made from limestone
Cement
Glass
Rock
What is thermal decomposition
The breaking down of something using heat
Write down the equation for the thermal decomposition of limestone
CaCO3 ——> CaO + CO2
How could you test for the carbon dioxide in a thermal decomposition reaction
Attach a bung with a cord from the thermally decomposition to a test tube of limewater the carbon dioxide will turn it cloudy
What product can be made by adding water to calcium oxide and why is it useful
Calcium hydroxide
Can be used to neutralise acidic soil as it’s an alkali
