earth

Question 1

what is the atmosphere

Answer 1

Key words
Atmosphere
The layer of air that surrounds the earth

Question 2

what is global warming

Answer 2

Global warming
The increase of surface temperature on the earth
Greenhouse gases
A gas that contributes to global warming by trapping the energy of the sun.

Question 3

what is the carbon cycle

Answer 3

Carbon cycle

A cycle showing the movement of carbon through our planet

Question 4

what are fossil fuels

Answer 4

Fossil fuels
A natural fuel such as coal, oil or gas, formed in the geological past from the remains of living organisms. They are non-renewable

Question 5

how are fossil fuels formed

Answer 5

Formation of fossil fuels
• Coal was formed from dead trees and other plant material
• Crude oil and gas were formed from dead marine organisms
Fossil fuels took a very long time to form and we are using them up faster than they can be replaced - once they have all been used up, they cannot be replaced. Fossil fuels are also finite resources. They are no longer being made or are being made extremely slowly.

Question 6

what it the green house effect

Answer 6

Greenhouse effect
Some gases in the atmosphere can trap escaping heat energy, causing some of it to pass back to the surface. These are called greenhouse gases, and they keep our planet warm, which is a good thing. Carbon dioxide is an important greenhouse gas. Increasing carbon dioxide levels

Question 7

how is global warming happening

Answer 7

Humans burn fossil fuels such as oil, coal and natural gas. The burning fuel releases waste gases, including carbon dioxide. As the human population increases, more fuel is used, and more carbon dioxide is released.

Question 8

what is global warming

Answer 8

More heat is trapped by the atmosphere, causing the planet to become warmer than it would be naturally. The increase in global temperature this causes is called global warming.

Question 9

what does the carbon cycle do

Answer 9

The carbon cycle
Carbon is being continually recycled on Earth. The processes that release carbon dioxide to the atmosphere include: 1. Combustion of fossil fuels 2. Respiration by plants and animals
Carbon dioxide is taken in from the atmosphere by plants so that they can carry out photosynthesis. Some processes move carbon compounds from place to place, including:
•feeding by animals
•formation of fossil fuels

Question 10

what is reactivity series

Answer 10

Reactivity series Orders the element based on reactivity

Question 11

what is a displacement reaction

Answer 11

Displacement reaction When a more reactive element displaces a less reactive element from it’s compound

Question 12

what is an ore

Answer 12

Ore A metal compound trapped in rock

Question 13

what is reduction with carbon

Answer 13

Reduction with carbon How metals below carbon are extracted from their compound

Question 14

what is electrolysis

Answer 14

Electrolysis

How metals above carbon are extracted from their compound

Question 15

what is oxidation

Answer 15

Oxidation is the gain of oxygen by a substance.
Magnesium + Oxygen → Magnesium Oxide
2Mg + O2 → 2MgO

Question 16

what is reduction

Answer 16

Reduction is the loss of oxygen from a substance.
Copper Oxide + Hydrogen → Copper + Water
CuO + H2 → Cu + H2O

Question 17

how can you extract metal

Answer 17

Methods of extracting metals
The method used to extract a metal from its ore depends upon the stability of its compound in the ore, which in turn depends upon the reactivity of the metal:
•The oxides of very reactive metals, such as aluminium, form stable oxides and other compounds. A lot of energy is needed to reduce them to extract the metal.
•The oxides of less unreactive metals, such as iron, form less stable oxides and other compounds. Relatively little energy is needed to reduce them to extract the metal.
So, the method of extraction of a metal from its ore depends on the metal’s position in the reactivity series.

Question 18

what is electrolysis

Answer 18

Electrolysis
When ionic compounds are molten or dissolved in water the ions are free to move. When electricity is passed through the liquid the compound
may be broken down into different substances.
Some important terms
•Electrolysis - the decomposition of a liquid using electricity
•Electrolyte - a liquid which conducts electricity
•Anode - the positive electrode
•Cathode - the negative electrode •Anode – the positive electrode
•Anions - negative ions - attracted to the anode
•Cations - positive ions - attracted to the cathode