Question

What is the atomic number for nickel?

Answer 1

Hint: To solve this question we first need to know what is atomic number. The atomic number Z of an element can be defined as the number of protons which are present in the nucleus of every atom of that element.

Complete answer:
Atomic number is also known as a proton number. A subatomic particle which has a positive electric charge of +1 is known as a proton.
There is at least one proton present in the nucleus of each atom and hence are a necessary part of the nucleus. They also are the defining property of an element.
Every element has a unique and different number of protons present, and hence every element has a unique atomic number.
Now, nickel has 28 protons in its nucleus hence its atomic number is 28.

Additional Information:
- The charge on electrons is -1 and has magnitude equal to the charge on protons.
- Nucleons are the particles which are present in an atomic nucleus and contain protons and neutrons. The mass of a neutron is slightly more than the mass of a proton.
number of neutrons = mass number - atomic number
Since the mass number of nickel is approximately 59, the number of neutrons in nickel is 31.

Note:
It should be noted that if there is no charge on the element, the number of electrons in the atom is equal to the number of protons or the atomic number. So nickel has 28 electrons and its electronic configuration is as follows:
$${}_{28}^{59}Ni=1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{8}4s^2$$