Which element below could be an isotope of beryllium

sodium-10

beryllium-10

boron-9

carbon-9

beryllium

Explanation:

isotopes are same elements

beryllium-10

Explanation:

First let's remember what an isotope is

Isotopes are atoms of the same element, whose nucleus have a different amount of neutrons, and therefore, differ in mass number.

Since isotopes are atoms of the same element, the only option that corresponds to beryllium is the option beryllium-10