When unstable elements lose particles and become more stable it is called

ions?

Explanation:

If it picks up or loses an electron, it becomes electrically charged and highly reactive. Such electrically charged atoms are known as ions. ... In an effort to achieve equilibrium, the atom emits particles in the form of radiation until the nucleus is stable. Such unstable atoms are said to be radioactive.

answer; i believe that the correct answer is (light);

b. the carbon cycle ensures living things have a source of hydrogen