Final answer:
The atomic number of an element (Z) equals the number of protons, and in a neutral atom, it also equals the number of electrons.
Step-by-step explanation:
The atomic number of an element is always equal to the number of protons in the nucleus of its atoms and the number of electrons in a neutral atom. The atomic number, often represented by the symbol Z, is a fundamental characteristic that defines the identity of an element.
An element's mass number, symbolized as A, is the sum of its protons and neutrons, making it possible to determine the number of neutrons by subtracting the atomic number from the mass number (A - Z = number of neutrons).