Elements are substances that contain only 1 kind of atom.
The Sun is currently a main sequence star and will remain so for another 4-5 billion years. It will then expand and cool to become a red giant, after which it will shrink and heat up again to become a white dwarf. The white dwarf star will run out of nuclear fuel and slowly cool down over many billions of years.
A. Fireworks exploding is the answer
CaCl2 is a good conductor of electricity when dissolved in water.
