science preperation
We breathe it and burn fuels in it. Plants use it to grow.
It is all around us but we hardly notice it except when the wind blows. Aircraft and birds fly in it. More than one hundred kilometres above us, satellites look down through it.
In the apparatus shown here, air is passed from one syringe to the other while the copper in the tube is heated. The oxygen from the air joins with the copper, so the volume of the air gets smaller.
The amount of oxygen in the air is the difference in volume before and after the air has been passed over the copper.
T
F
Scientific data, shown in the table below, tell us that nearly all the air is nitrogen, oxygen and argon. Less than 0.1% of dry air is made up of all the other gases. These percentages are almost the same all over the Earth. Only the percentage of water vapour varies, between 0% and 1%, because the water can condense to form clouds and rain. air passing through copper
syringe
25
50
75
100
A
R
D
pour is
Water va f the air. Dry part o ater that is ith the w air is air w oved. Clouds m vapour re lets of liquid are drop or ice. water copper
25
syringe
ut!
Watch o a gas
100
What is air?
How we know what’s in the air
75
The air around us
C1 Air quality
50
We are learning to:
> describe the composition of the air
> explain the properties of air as a gas
> explain how the true value of a quantity is estimated
heat
FIGURE 3: This apparatus can be used to find out how much oxygen there in the air.
FIGURE 1: The atmosphere forms a layer about 100 km thick over the surface of the Earth. It is made up of air, clouds and dust.
Substance
% in dry air
nitrogen oxygen The substances that make up the air
Air is a gas. It is a mixture of lots of different substances, which are all gases. The most common gases in air are nitrogen, oxygen and argon. There is also water vapour, carbon dioxide and many other
It is all around us but we hardly notice it except when the wind blows. Aircraft and birds fly in it. More than one hundred kilometres above us, satellites look down through it.
In the apparatus shown here, air is passed from one syringe to the other while the copper in the tube is heated. The oxygen from the air joins with the copper, so the volume of the air gets smaller.
The amount of oxygen in the air is the difference in volume before and after the air has been passed over the copper.
T
F
Scientific data, shown in the table below, tell us that nearly all the air is nitrogen, oxygen and argon. Less than 0.1% of dry air is made up of all the other gases. These percentages are almost the same all over the Earth. Only the percentage of water vapour varies, between 0% and 1%, because the water can condense to form clouds and rain. air passing through copper
syringe
25
50
75
100
A
R
D
pour is
Water va f the air. Dry part o ater that is ith the w air is air w oved. Clouds m vapour re lets of liquid are drop or ice. water copper
25
syringe
ut!
Watch o a gas
100
What is air?
How we know what’s in the air
75
The air around us
C1 Air quality
50
We are learning to:
> describe the composition of the air
> explain the properties of air as a gas
> explain how the true value of a quantity is estimated
heat
FIGURE 3: This apparatus can be used to find out how much oxygen there in the air.
FIGURE 1: The atmosphere forms a layer about 100 km thick over the surface of the Earth. It is made up of air, clouds and dust.
Substance
% in dry air
nitrogen oxygen The substances that make up the air
Air is a gas. It is a mixture of lots of different substances, which are all gases. The most common gases in air are nitrogen, oxygen and argon. There is also water vapour, carbon dioxide and many other