Properties and Units

If someone was given a glass bottle and asked to describe it, they might start by describing its colour and its shape. Then they might get a ruler and measure its height and its width, or they might use weighing scales to measure its mass. All of these things are the properties of the bottle. In other words, a property is a characteristic that something has.

The properties of a bottle include its height, width, colour, mass and volume.

The properties of a bottle include its height, width, colour, mass and volume.

Properties are important in Chemistry

In this course, we are going to learn about a lot of different properties. When we are studying particles, the main properties we are going to be interested in are their mass and charge. Later in the course, when we are learning about solids, liquids and gasses, we will think about many different properties of them, including their density, volume and concentration.

Many properties are numbers

Many properties are described using numbers. Examples of such properties include mass, charge, volume, concentration and density.

Some properties are described using words rather than numbers. For example, colour ('the bottle is greenâ€™).

Properties that are described using numbers often have units.

A unit is a specific amount used to describe something

In order to describe things that are numerical, we often need to use units, such as centimetres for length, or minutes for time.

A unit is a specific amount of something that has been agreed on for the purpose of measuring. For example, a centimetre is a specific amount of length - every ruler and measuring tape has centimetres that are the same length. Therefore by saying how many centimetres long something is, you can communicate its length to other people and they will know exactly what you mean.

Most units have an abbreviation - a shorter way of writing them. For example, the abbreviation for centimetres is cm and the abbreviation for seconds is s.

Flashcards

Flashcards help you memorise information quickly. Copy each question onto its own flashcard and then write the answer on the other side. Testing yourself on these regularly will enable you to learn much more quickly than just reading and making notes.

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What is a property?

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What is a unit?