How could you build an electrical circuit?

You could build an electrical circuit using a power source, wires, a switch and a resistor.

What are the characteristics of light?

Light can come from different sources: artificial and natural.
Light can be reflected and refracted. When light relfects it bounces from the surface of the object. When the surface is smooth all the rays reflect in the same direction. If the surface is rough they relfect in different directions; when light refracts light changes direction because it passes from one substance to another with a different density

What is the difference between  insulators and conductors?

The difference that insulators do no transfer heat effectively and conductors, on the other hand, can transfer heat quickly and effectively.

What is magnetism?

Magnetism is the abilty to attract magnetic materials. To do this we use magnets.