Hydrogen

• gas• the most abundant element in the Universe • colourless• odourless• flammable• the lightest element

Universe

Living things

Earth's crust

H2Hydrogen

Sun

83.9 %

63 %

0.22 %

Helium

• a noble gas • formed by single atoms• lighter than air• not flammable

He

1868 – It was first discovered on the Sun during a solar eclipse.

eclipse

helium

helium balloons

Universe

Helium

15.9 %

• the most abundant gas in the atmosphere • colourless• odourless• inert

Nitrogen

Living things

N2

Atmosphere

nitrates

proteins

Nitrogen

78 %

1.4 %

• gas • colourless• odourless• the most abundant element on Earth

Oxygen

21 %

25.5 %

47 %

Oxygen

O2

water

H2Oozone

O3

Living things

Earth's crust

Atmosphere

• the basis of all organic compounds• has a unique ability to form compounds

graphite

Carbon

0.03 %

9.5 %

0.19 %

Living things

Earth's crust

Atmosphere

Carbon

C

coal

oilcarbon dioxide

2.2 %

Elements in the Earth's crust

3.5 %

4.5 %

7.9 % Aluminium

Iron

Calcium

Magnesium

28 % Silicon

47 % Oxygen (O)28 % Silicon (Si)7.9 % Aluminium (Al)4.5 % Iron (Fe)3.5 % Calcium (Ca)2.5 % Sodium (Na)2.5 % Potassium (K)2.2 % Magnesium (Mg)

28 % Silicon

Elements in the Earth's crust

quartz

microchip

silica (SiO2)

• solid substance• brown colour• generally found as a compound

7.9 % Aluminium

Elements in the Earth's crust

micas

feldspars

• soft, light metal• light grey colour• only found as a compound• obtained from bauxite

• metal • grey colour • generally found as a compound

4.5 % Iron

Elements in the Earth's crust

pyrite

hematite

steel

iron and oxygen

iron and sulphur iron and carbon

2.2 %

talc

Elements in the Earth's crust

• metal • silver-white colour• found as a compound

olivine fireworks

Magnesium

• metal • greyish white colour• found only as a compound

Elements in the Earth's crust

limestone stalactites

calcite

calcium carbonate

3.5 %

Calcium

Elements in sea water

composition of sea water

characteristics of water

Chlorine

Sodium

Potassium

Elements in sea water

• yellowish green gas• denser than air• irritating and toxic• used to disinfect swimming pools

Chlorine

Sodium

Potassium

composition of sea water

characteristics of water

Elements in sea water

• metal• soft • shiny• only found in compounds• reacts easily with oxygen

Sodium

halite

Potassium

Chlorine

composition of sea water

characteristics of water

Elements in sea water

• metal• soft• shiny• only found in compounds

Potassiumpotassium chloride

Chlorine

Sodium

composition of sea water

characteristics of water

Elements in sea water

CLOSEBACK

composition of sea water

Salts Grams per litre

sodium chloride 24

magnesium chloride 5

sodium sulphate 4

calcium chloride 1.1

potassium chloride 0.7

sodium bicarbonate 0.2

others 0.5

TOTAL 35.5

Average chemical composition of sea water

Potassium

Chlorine

Sodium

characteristics of water

Water

water molecules

(H2O)

hydrogen bridges

68 % waterGO BACK

characteristics of water