How many protons and electrons are in a Cu 2+ ion?
64
29
A 27 protons, 29 electrons
27 protons, 31 electrons
B
29 protons, 27 electrons
D
29 protons, 31 electrons

B  29 protons, 27 electrons

Explanation:

The given specie is copper ion:

         Cu²⁺  

We are to find the number of protons and electrons it contains.

 The number of protons is the positively charged particles in the atom.

 Electrons are the negatively charged particles in the atom.

The number of protons is the same as the atomic number

Atomic number of copper  = 29

 Number of protons  = 29

 Now;

    Charge  = Number of protons  - Number of electrons

     2  = 29  - number of electrons

     -27  = - number of electrons

 Number of electrons  = 27

1. they vary with a higher number because boiling is way hotter than melting