Answer: The atomic number of an atom that has 6 protons, 6 neutrons, and 6 electrons is 6.
Explanation:
Atomic number is defined as the number of protons or number of electrons that are present in an atom.
For a neutral atom:
Atomic number = Number of electrons = Number of protons
Given : Number of electrons = Number of protons = 6
Thus atomic number = 6
Mass number is defined as the sum of number of protons and neutrons that are present in an atom.
Mass number = Number of protons + Number of neutrons
Given: Number of neutrons = 6
Thus mass number = Number of protons + Number of neutrons = 6+ 6= 12.
The atomic number of an atom that has 6 protons, 6 neutrons, and 6 electrons is 6.