Question

which of these has 28 protons and 26 electrons?
o fe
o fe²⁺
o ni
o ni²⁺

Explanation:

Step1: Recall atomic number concept

The atomic number is equal to the number of protons. Nickel (Ni) has an atomic number of 28, so it has 28 protons.

Step2: Analyze ion - electron relationship

A neutral atom has an equal number of protons and electrons. If an atom has 28 protons and 26 electrons, it has lost 2 electrons and has a + 2 charge.

Answer:

D. $Ni^{2+}$