which atom gives up its electrons most easily? br f na rb

Brief Explanations:

Ionization energy is the energy required to remove an electron from an atom. Atoms with lower ionization energy give up electrons more easily. Ionization energy decreases down a group in the periodic table and increases across a period. Among the given elements, Rb (rubidium) is in Group 1 and has the largest atomic radius among them. Larger atomic radius means the outermost electron is farther from the nucleus and is held less tightly, resulting in lower ionization energy. Br (bromine) and F (fluorine) are non - metals in Group 17 and have high ionization energies as they tend to gain electrons. Na (sodium) is also in Group 1 but has a smaller atomic radius than Rb, so its ionization energy is higher than that of Rb.

Answer:

Rb