Atomic nucleus: the atomic number of an atom is equal to the number of what particles in the nucleus? :
a)
positrons
b)
protons
c)
neutrons
d)
electrons
e)
nucleons

B) protons

Explanation:

The total number of protons in an atom represents the atomic number of that element. An element is generally expressed as

Where,

A is the element

N is the Mass number i.e., the number of neutrons and protons in an atom.

Z is the atomic number.

The elements are arranged according to their atomic number in the modern periodic table.