Question

How many protons, neutrons and electrons are in the ion ⁶⁴Cu²⁺?

Answer 1

Given Ion Cu²⁺.

Atomic Number of Cu = 29

Mass Number of Cu = 64 (as given in the question)

We know number of protons = Atomic Number of of atom

Therefore, number of protons = 29

We also know that number of electrons = number of protons, if the atom is nonionic. However, the atom in question is ionic (Cu²⁺). Since one electron has -1 charge, +2 means atom has lost 2 electons.

Therefore, number of electrons = 29 - 2 = 27

Number of neutrons = Atomic Mass of the atom - number of protons

Given Atomic Mass of Cu²⁺ = 64,

Therefore, Number of neutrons = 64 - 29 = 35

However, if exact atomis mass of Cu is considered (which is 63.456), Number of neutrons = 63.456 - 29 = 34

Answer:

Number of protons = 29

Number of electrons = 27

Number of neutrons = 35 (if atomic mass of considered to be 64) or 34 (if atomic mass if considered to be 63.456)