Question 4.7: Calculating Numbers of Protons, Neutrons, and Electrons As a...
Calculating Numbers of Protons, Neutrons, and Electrons
As a micronutrient, zinc is needed for metabolic reactions in cells, DNA synthesis, the growth of bone, teeth, and connective tissue, and the proper functioning of the immune system. For an atom of zinc that has a mass number of 68, determine the following:
a. the number of protons b. the number of neutrons c. the number of electrons
| Element | Atomic Number |
Mass Number |
Number of Protons |
Number of Neutrons |
Number of Electrons |
|
| ANALYZE THE PROBLEM |
Zinc (Zn) |
30 (periodic table) |
68 | equal to atomic number |
mass number – number of protons |
equal to number of protons |
a. Zinc (Zn), with an atomic number of 30, has 30 protons.
b. The number of neutrons in this atom is found by subtracting number of protons (atomic number) from the mass number.
Mass number – atomic number = number of neutrons
68 – 30 = 38
c. Because the zinc atom is neutral, the number of electrons is equal to the number of protons. A zinc atom has 30 electrons.