The core of the sun is

home to billions and billions of atoms of hydrogen, the lightest element in the universe. The immense pressure and heat pushes these atoms so close to one another that they squish together to create new, heavier atoms. This is called nuclear fusion.

4

explanation:

4

explanation: magnetic pole, region at each end of a magnet where the external magnetic field is strongest. the south-seeking pole, or any pole similar to it, is called a south magnetic pole. unlike poles of different magnets attract each other; like poles repel each other.