The north pole of one magnet pulls the south pole of another magnet towards it. Two poles that are the same, for instance, two north poles, will repel each other and two poles which are opposite, for instance, north and south will attract each other. A compass uses magnets to help people find their way around. The compass needle is actually a little magnet that always points north. Magnets will attract metal objects such as screws, cutlery, and nails.
Trees are the largest and longest living plants on Earth.
When a tree is cut down the inside of the trunk will tell you how old the tree is. The trunk will display a series of light and dark rings. Each light ring shows the trees grow in the summer months and each dark ring shows the trees growth in the winter months. Therefore if you count each light and dark ring to be one year you can work out how old the tree is. Scientists use a more accurate method of dating trees these days.