Which of the following has the maximum number of neutrons?

The electronic configuration of a divalent metal ion $M^{2+}$ is $2, 8, 14$ and its atomic mass is $58 \, a.m.u.$ What is the number of neutrons in its nucleus?

$A$ monoatomic anion $(A^-)$ has $45$ neutrons and $36$ electrons. The atomic mass, group in the periodic table, and physical state at room temperature of the element $(A)$ are respectively:

Which property of an element is always a whole number?

Substances which have identical chemical properties but differ in atomic weights are called

Addition of two neutrons in an atom $A$ would