Matter

Matter can exist in lots of different ways that we call states. Solids, liquids, and gases are the states we are most likely to often see in our everyday lives. 

The table below shows the movement of particles and their arrangement (how they are placed) for each state:

State of Matter	Image Credit This work by The Schools' Observatory is licensed under All rights reserved	Image Credit This work by The Schools' Observatory is licensed under All rights reserved	Image Credit This work by The Schools' Observatory is licensed under All rights reserved
Particle Arrangement	Packed tightly in ordered rows	Random (but still touching) with some space between them	Random (and not touching) with lots of space between them
Particle Movement	Vibrate in place	Flow past each other	Move quickly in random directions
Forces between Particles	Strong	Weaker	Weakest

This means that each state has certain properties:

Whilst we mostly focus on solids, liquids, and gases, there are other states of matter too. Plasma is another example. These are very high temperature and high energy substances with positive and negative charges in them. This creates electric and magnetic fields in the plasma, making it able to conduct electricity.

Most matter in the universe exists as plasma inside stars, nebula, and the space between galaxies. Some examples of plasma on Earth are lightning, the aurora (Northern or Southern lights), and neon lights.

Matter can change state when it is heated or cooled.

Image

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This work by Enoshd/The Schools' Observatory is licensed under Creative Commons Attribution Share Alike 4.0 International

Imagine heating up ice. The particles will get energy and start to vibrate faster. This increases the temperature. But since ice is a solid, the particles will stay in ordered rows because of the strong forces between them.

Eventually though, once enough energy has been given, they can overcome these forces a little. At this point, the particles keep moving at the same speed but spread further apart – the substance changes state. Temperature doesn’t change because the movement hasn’t changed, only the arrangement.

The ice has melted into liquid water. If we heated the water, the same thing would happen again. Firstly, the particles move faster and the temperature goes higher. When they have enough energy, their speed will stay the same but they’ll move further apart. The water has boiled to become steam – a gas.

Image

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This work by Bohrium2b/The Schools' Observatory is licensed under Creative Commons Attribution Share Alike 4.0 International

The opposite happens when something is cooled down. Energy is taken from the particles, slowing down their movement and decreasing the temperature. When they are moving slowly enough, the forces can pull them closer together. This changes the arrangement of the particles, and a change of state happens.

Image

Credit

This work by Kelvinsong is licensed under Creative Commons Attribution 4.0 International

Density is how much mass there is in a given volume (or space). The more mass in that space, the greater the density of the substance.

We can calculate density using the equation:
Density = Mass ÷ Volume.
 

Density is measured in kilograms per metres cubed (kg/m³) or grams per centimetres cubed (g/cm³).

The density of an object can affect whether it will float or sink.

Objects that are denser than water will sink, and those that are less dense will float.