Magnetic Attraction

Magnetic Attraction is used to separate magnetic materials from not-magnetic materials.

Filtration

Filtration is used to separate an insoluble solid from a liquid solid mixture. This mixture is also known as a suspension.

Filtration is used quite commonly in our everyday lives. For example, the filter in fish tank and air conditioner units, washing of vegetables using sieves and making tea using teabags.

Evaporation

Another method to separate mixtures is evaporation till dryness. It is used to separate dissolved solids from a solid-liquid mixture. This method is only effective if the solid that is dissolved has a high melting point. This means that it will not melt or decompose when heated.

Light is a form of energy that enables us to see things around us when it enters our eyes. Light travels at high speeds in straight lines. It can travel at a speed of 300000000 meters per second in a vacuum.

There is a difference between a light ray and a light beam. A light ray has a thin line of light while a light beam has a stream of light. There are three types of beams of light. A parallel beam, a divergent beam which fan outwards and a convergent beam which merges to a point.

How do you think shadows are made? It is made when light is shone at an object and some light rays are blocked by the object while others continue to travel in straight lines. An object which will block light rays is called an opaque object. the light behind the opaque object is know as a shadow. An eclipse is also formed the same way. when the moon comes between the sun and the earth, the moon blocks the light from the sun and casts a shadow on Earth.