Compound are formed by two or more elements chemically combined. For example: H^2O is the water formula, this is a compound because you two elements which are Hydrogen and Oxygen and together they form a compound. The (^2) is the amount of atoms the formula has, in this case Hydrogen has two atoms and Oxygen is neutral.
When you combine protons and neutrons in the electrical charge they combine to make electricity
Strontium (Sr). Elements in the same group of the periodic table have similar characteristics.
It is b have a great rest of your day