Question

an atom of element be has four protons, four electrons, and five neutrons. which element below could be an isotope of this atom? sodium - 10 beryllium - 10 boron - 9 carbon - 9

Explanation:

Isotopes are atoms of the same element with different numbers of neutrons. The given atom is of element Be (beryllium). So, the isotope must also be of beryllium. Among the options, only beryllium - 10 is of the element beryllium.

Answer:

beryllium - 10