Tools to control and detect light Telescope Microscope Binoculars Cameras
Energy and electricity Oil, gas and coal are PRIMARY sources of energy. Electricity is a SECONDARY source of energy. We transform other sources of energy to make electricity. Electricity is transformed in power plants.
Matter Matter is made of atoms. Atoms are made of electrons, protons and neutrons. When electrons move along wires, electricity is produced.
Conductors Materials that allow electricity to flow, like metals, are called CONDUCTORS.
Insulators Materials that don’t allow electricity to pass, like rubber and plastic, are called INSULATORS.
Using energy Energy cannot be created or destroyed, but it can be transformed into other types of energy: - Batteries into light energy. - Electrical energy on phone into sound energy.
Uses of Energy Industry: heat for steam or hot water, factories for cooking, drying etc. Transportation: gasoline, diesel, electricity, gas, etc. for vehicles. Public and residential use: electricity and gas for heating and lighting in offices, hospitals, schools and homes.
Clean energy Non-renewable sources of energy like coal, oil and natural gas cause air pollution. Renewable energy like sunlight, wind or water is good. It replaces itself and doesn’t cause pollution.