What is a chemical change. provide examples

Nonmetal halogen family atmoic mass 35

In the 1800s, one of the statements in john dalton's atomic theory was that atoms are indivisible. later experimental evidence led to the discovery of subatomic particles such as neutrons, electrons, and protons. what happened to the indivisible atom part of dalton's atomic theory, and why?

Which of the following electromagnetic waves can create ions?