AP BIOLOGY

Detailed explanation-1: -All atoms of an element have the same number of protons, and every element has a different number of protons in its atoms. For example, all helium atoms have two protons, and no other elements have atoms with two protons.

Detailed explanation-2: -Atoms of a particular element must have the same number of protons but can have different numbers of neutrons. When an element has different variants that, while all having the same number of protons, have differing numbers of neutrons, these variants are called isotopes.

Detailed explanation-3: -Adding or removing protons from the nucleus changes the charge of the nucleus and changes that atom’s atomic number. So, adding or removing protons from the nucleus changes what element that atom is! For example, adding a proton to the nucleus of an atom of hydrogen creates an atom of helium.

Detailed explanation-4: -The number of electrons in a neutral atom is equal to the number of protons. The mass number of the atom (M) is equal to the sum of the number of protons and neutrons in the nucleus.