A steel ball bearing is attracted to a magnet because of the magnetic properties of steel. Steel is a ferrous metal, which means it contains iron. Iron is a strongly magnetic material, and when it is magnetised, it can create a magnetic field. This magnetic field can then attract other ferrous metals, such as steel ball bearings.

The strength of the attraction between a magnet and a steel ball bearing depends on a number of factors, including the strength of the magnet, the size of the steel ball bearing, and the distance between them. The closer the steel ball bearing is to the magnet, the stronger the attraction will be.

The attraction between a magnet and a steel ball bearing is an example of magnetism, which is a fundamental force of nature. Magnetism is responsible for the behaviour of magnets, and it is also used in a variety of applications, such as electric motors, generators, and compasses.