Nickel has chemical symbol ni and the atomic 28. how many protons, neutrons, and electronic would be found in an atom of nickel-78

Explanation:

Atomic number is the sum of only total number of protons present in an element. Whereas mass number or atomic mass is the sum of total number of both protons and neutrons present in an element.

For example, given atom of Ni has atomic number 28.  And, it is known that atomic mass of Ni is 58 g/mol.

Therefore, number of neutrons present in it will be calculated as follows.

                    Mass number = no. of protons + no. of neutrons

                         58 = 28 + no. of neutrons

                    no. of neutrons = 58 - 28  

                                               = 30

Also, when an atom is neutral in nature then its number of protons equal to the number of electrons present in it.

Hence, we can conclude that in a neutral atom of Ni there are 28 protons, 30 neutrons and 28 electrons.