Below are some nuclei containing different numbers of protons and neutrons. Which one is an isotope of potassium? * A)20 protons, 20 neutrons
B) 17 protons, 22 neutrons
C) 18 protons, 21 neutrons
D) 19 protons, 19 neutrons

radioactive decay occurs in unstable atomic nuclei – that is, ones that don't have enough binding energy to hold

the nucleus together due to an excess of either protons or neutrons.

every chemical equation adheres to the law of conservation of mass, which states that matter cannot be created or destroyed. therefore, there must be the same number of atoms of each element on each side of a chemical equation.