Electrical current running through a wire causes that wire to heat up.
An electrical current is a flow of electrons.
A flow of electrons running through a wire causes that wire to heat up.
what can run through a wire causing it to heat up?

1: flow of electrons
2: electromagnetic energy
3: flow of neutrons
4: kinetic energy
5: hydrogen and oxygen
6: chemical messengers
7: flow of protons
8: h2o