Questions

All atoms of an element have the same number of protons. The number of protons in an element is a primary identifier known as its atomic number. The number of electrons is the same as the number of protons.

The nucleus of an atom is the densest part of an atom. It contains the protons and neutrons of an atom.

Burning gasoline is the only process that involving in a chemical change in the given options. A chemical change is a change in the starting substances that are called reactants from the formed new substances that are called products.