Matter

Glossary:

• Atom�Basic building blocks of all substances.
• Compound�Substances containing two or more types of atom.
• Condensation�Change in state from gas to liquid.
• Element�Substances made of only one type of atom.

​

​

​

​

​

• Freezing�Change in state from liquid to solid.
• Melting�Change in state from solid to liquid.
• Periodic Table�This is how scientists organise all of the known elements.

​

​

​

​

​

​

​

​

Particles

• If we could divide any substance down into smaller and smaller pieces we could see it is made of tiny particles.
• These particles are so small they could not be seen using a microscope.
• We can represent these particles in models using spheres.

​

​

​

​

​

​

States of matter

• Three states of matter are solid, liquid and gas.

​

​

​

​

Differences in states of matter

• In solids the particles are closely spaced and vibrating. In liquids there is random motion but the particles are in contact.
• In a gas there is random motion and the particles are widely spaced.
• Liquids and gases flow and completely fill their container. Gases can be �compressed.

​

​

​

​

​

Changes in states of matter

​

​

​

• A solid melts when it is heated because the particles are gaining energy. This energy is used to break the forces of attraction between the molecules. The more energy a particle has the faster it can move.

​

​

​

​

​

Matter

Atoms and elements

• Atoms are the basic building blocks of all living and �non-living things anywhere in the universe.
• There are just over 100 different types of atom.
• Substances made of only one kind of atom are called elements.
• All the known elements are listed

in the periodic table of elements.

​

​

​

​

​

​

Compounds

• Atoms of different elements can combine together to form a very large number of compounds.

​

​

​

​

​

Activities

• Explain how a solid melts in terms of energy and forces between particles.

​

• Explain why ice and iron have different melting points. Your answer should consider the forces of attraction between the particles.

​

• Rock salt contains sand and salt. A student mixed rock salt in warm water. Describe how the student would separate out the sand, salt and water from the mixture formed. You will need to consider the question carefully as the water needs to be collected too.

​

• Explain the difference between an atom, an element, a compound and a mixture using the gases found in air as examples. Substances you could use in your answer include: oxygen, carbon dioxide and argon.

​

• When a volcano erupts liquid rock (magma) is released along with hot gases. The magma cools and turns into solid rock.
1. Describe the changes in the movement of the particles in the magma as it cools.
2. Describe the arrangement of particles in the hot gases and explain how they are different to those in a liquid.

  QUICK QUESTIONS:

1. Draw diagrams representing the particles in a solid, liquid and gas.
2. Describe how the particles move in a solid, liquid and gas.
3. State the name of the process in each of the following changes:
2. Solid to liquid
3. Liquid to solid
4. Gas to liquid
5. Liquid to gas.

​