Chapter 1: Planet Earth

Question 1

What is the carbon cycle?

Answer 1

a process that store and moves carbon

Question 2

Why do humans need nitrogen?

Answer 2

nitrogen makes up proteins in body which helps with growth and repair

Question 3

How do living organisms get the nitrogen that they need?

Answer 3

nitrogen atoms can’t easily be broken down but some plants have bacteria that can fix nitrogen from the air so that they can use it. If other living organisms then eat the plants they get their nitrogen in.

Question 4

Define combustion:

Answer 4

a chemical reaction that occurs between fuel and an oxidizing agent also called burning

Question 5

What is the greenhouse effect?

Answer 5

when earth’s atmosphere becomes thick with gases and substances that trap sun rays and the earth becomes warmer.

Question 6

What are the greenhouse gases?

Answer 6

any gas that interacts with infrared radiation emitted by earth.
carbon dioxide
methane
water vapour
also (nitrous oxide, N20 and ozone, 03)

Question 7

What is a mineral?

Answer 7

a naturally occurring solid, inorganic, crystalline substance having a fairly definite chemical composition and fairly definite physical properties.

Question 8

What are ores?

Answer 8

rocks that contain minerals of economic value

Question 9

What is marble?

Answer 9

limestone that has been compressed and heated and is harder than limestone

Question 10

What are some of the limestone uses?

Answer 10

used to make cement
neutralizes acid waste from the extraction of gold and uranium
used as a fluxing agent in iron blast furnaces

Question 11

What are some lime uses?

Answer 11

production of paper
as a flocculent to remove impurities in sugar extraction and water purification
to reduce acidity of fertilizers in soil
as an animal feed to produce calcium

Question 12

Define fuels:

Answer 12

store energy until we do something to them and use the energy released

Question 13

What is an energy resources?

Answer 13

something that we harness to get it’s energy for a useful task.

Question 14

How do people use hydrogen as an alternative fuel?

Answer 14

they use electricity to break up hydrogen that is combined with other atoms so that it can be used.
hydrogen is a good energy source because it releases a lot of energy without creating pollutants

Question 15

What is the hydrogen fuel cell?

Answer 15

an electrochemical fuel cell that combines hydrogen and oxygen to produce electricity.
(a chemical reaction takes place at two electrodes, which are joined by a conductive wire, allowing a flow of electrons between the two and producing an electric current)

Question 16

How is acid rain formed?

Answer 16

nitrogen and oxygen in air;
react at high temperatures / in engines;
to form oxides of nitrogen or named oxide of nitrogen;
(reacts in air / with water to form) nitrous / nitric acid;