NATURAL SCIENCE: ENERGY AND MATTER

ENERGY AND MATTER

What is energy?

Energy is the ability to do work. There are two groups of energy sources, Renewable and Non-Renewable energy.

Non-renewable energy includes coal, gas and oil. Most cars, trains and planes use non-renewable energy. They are made by burning fossil fuels to create energy.

Renewable energy includes solar, hydro and wind energy. Wind energy is made when the wind moves the blades on a wind turbine. This movement creates wind energy which is converted into electrical energy.

MACHINES

Simple machines

Simple machines make our lives easier by helping us with our workload. We will describe and give examples of the six types of simple machines.

MATTER, MATERIALS AND FORCES

1. PHYSICAL CHANGES

Matter has three forms: solid, liquid and gas. A physical change occurs when matter changes shape or state. Physical changes happen to water in the water cycle. 

A physical change also occurs when we break a glass vase. We change the appearance of the vase but the pieces are still glass and have the same chemical properties as before.

2. MASS, VOLUME AND DENSITY

Mass is the amount of matter something contains. An apple has a greater mass than a grape. We can measure mass in grams (g). 

1000 grams = 1 kilogram.

Volume is the amount of space that something occupies. A car has a greater volume than a bicycle. We can measure volume in millilitres (ml)

1000 millilitres = 1 litre.

DENSITY

We can calculate density by dividing the mass of an object by its volume. The unit of measurement is kilograms per litre (kg/l).

It helps to explain why objects float on water and others sink. For example, cork has a lower density than the water, that is why it floats. Iron has a higher density than water, for this reason it sinks.