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Science describes phenomena (processes and occurrences) that take place around you, in nature.

Biology is the study of living things in nature.

Physics is about force, sound, light, motion, electricity, temperature and energy.

Chemistry is all about substances and their reactions. A chemical reaction changes substances into different substances.

Everyday situations often involve both physics and chemistry.

The applications of science are everywhere around you. Scientists are essential to our society. They control the tap water, check if there are no pesticides on your apple. But not all science is good. Almost all discoveries can be used for bad as well as good purposes. Nuclear power can provide a solution for our energy needs, but it can also be used to produce atomic bombs.

Observation is very important in physics and chemistry. You can use your five senses to make observations:

feel with your skin, taste with your tongue, smell with your nose, hear with your ears and look with your eyes. You can feel is something is hot, cold, hard, soft. You can taste if something is sweet, salty, bitter or acidic. You can smell all sorts of smells. You can hear sounds and determine which direction they come from. You can see shapes and colour, and estimate how far away something is. Observation by the senses can be unreliable or unsafe. It is therefore better to use a measuring instrument. You often need to think of conclusions using your brain, from your observations.

When scientists talk about mass, they mean the number of kilograms of an object or material. Every object and material has a mass. The mass (m)  is the number of kilograms (kg) of that object or material.

1 kg = 1000 g

1 g = 1000 mg

Mass and weight are not the same. Kilo and kilogram also aren’t the same.

Volume and capacity are related to space, but they aren’t exactly the same thing. The volume of an object gives how much space that object occupies, that is, how big the object is. The capacity of an object gives how much space there is in it: the object is therefore hollow. The unit for volumes and capacities is cm³.

1 dm³ = 1000 cm³ = 1 L

1 ml = 1 cm³

1 L = 1000 ml

You can accurately measure the volume of liquids with a measuring cylinder. Position your eye level with the surface of the liquid, then read off the height of the liquid at the centre of the cylinder.

You can determine the volume of a block using the formula: volume = length x width x height.