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Free online chemistry lesson for elementary school, middle school and high school.
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Mechanics lessons
Water on Earth
Changes of state in the nature: the water cycle
Water in human body
Test for water
Properties of water in different states
States of matter
States of matter and its changes
Boiling water
Water: freezing and melting
Changes of state: mass and volume
Molecules in different states of matter

Mixtures and solutions
Heterogeneous mixtures
Homogeneous mixtures
Vaporization of water
Dissolving a solid in water
Conservation of mass on dissolving
Miscibility in water

Mass and volume
Volume and its units
Measuring volume with a graduated cylinder
Mass and its units
Measuring the mass of a liquid
Mass of a liter of water

Air and atmosphere
Earth's atmosphere protect us
Threats to the Earth's atmosphere
Composition of air
Air and life
Atoms and molecules
Molecules in mixtures and pure substances
Molecules and states of matter
Composition of molecules
Constituents of the atoms
The electrical neutrality of the atom

Basics of combustion
The combustion of carbon
The combustion of butane
Atoms and chemical reactions
Chemical reactions
Chemical equations
Law of conservation of mass
Chemical synthesis

Most common metals

How to distinguish metals ?

Corrosion of metals

Electrical conductivity of solid materials

Electrons and free electrons

Electric current in metals
The conductivity of aqueous solutions
Aqueous solutions and ions
The direction of movement of ions
Formation of ions
Tests for ions
Acidic and basic solutions
pH of aqueous solutions
Ions in acidic and basic solutions
Dilution of acids and bases
Composition of hydrochloric acid
Chemical reaction between iron and hydrochloric acid

Electrochemical cells and chemical energy
Chemical reaction beteween a copper sulphate solution and zinc
Copper sulfate and zinc battery
Basics of electrochemical cell



Mass and volume

Volume and its units

1) What is volume ?

The volume corresponds to the space occupied by an object or substance (solid, liquid or gaseous).

The volume can be calculated for simple geometric shapes such as
- Cubes: Volume = side x side x side
- Parallelepiped: Volume = length x width x height
as well as spheres, cones, pyramids etc..

For objects of more complex shapes, we must make measurements to determine the volume

2) Units of volum: cubic meter

The standard unif of volume is the cubic meter ( symbol m3 ).
A cubic meter corresponds to the space occupied by a cube of side 1 m.

L'unité de volume du système international est le mètre cube de symbole m
Un mètre cube correspond à l'espace qu'occupe un cube de 1 m de coté.

The volume can also be expressed using multiples of the cubic meter:
- The cubic decameter (da
- The cubic hectometer (h
- The cubic kilometers (k
Or using submultiples of the cubic meter:
- The cubic decimeter (d
- The cubic centimeter (c
- The cubic millimeter (m

Each unit is a thousand times greater than the previous one:
1 cubic centimeter is equal to 1000 cubic millimeter.
1 cubic decimeter is equal to 1000 cubic centimeter.
1 cubic meter is equal to 1000 cubic decimeter.

Each quantity expressed in one of these units can also be expressed in any of the other. This change of units can be achieved using a conversion table:

 km3  hm3 dam3   m3  dm3  cm3  mm3



3) Units of volum: litre

For liquids and gases, it is common practice to use as unit volume litre (L) and its derived units:
- Millilitre (mL)
- Centilitre (cL)
- Decilitre (dL)
- Decalitre (dal)
- Hectolitre (hl)
- Kilolitre (kL)

Each of these units is ten times greater than the previous one:
1 centilitre is equal to 10 ten millilitre.
1 deciliter is equal to 10 centilitre.
A litre is equal to 10 decilitre.

Each volume expressed in one of these units can be converted to another unit using the following conversion table:

kL hL daL L   dL cL mL
4) Cubic meter and litre

A litre is a unit that was defined as being equal to one cubic decimeter:
1 L = 1 d
Therefore we have also the following equality:
1 mL = 1 c