How many protons, neutrons, and electrons are in this ion?

[tex]{ }_{25}^{55} \text{Mn}^{2+}[/tex]

A. 25 p^{+}, 30 n^{0}, 23 e^{-}
B. 25 p^{+}, 55 n^{0}, 25 e^{-}
C. 25 p^{+}, 30 n^{0}, 25 e^{-}
D. 30 p^{+}, 25 n^{0}, 25 e^{-}



Answer :

To determine the number of protons, neutrons, and electrons in the given ion [tex]\(\ce{^{55}_{25}Mn^{2+}}\)[/tex], let's break down the problem step-by-step.

1. Number of Protons:
- The atomic number, which is given as 25, represents the number of protons in the atom.
- Therefore, the ion has [tex]\(25\)[/tex] protons.

2. Number of Neutrons:
- The mass number, which is given as 55, represents the total number of protons and neutrons in the nucleus.
- To find the number of neutrons, subtract the number of protons from the mass number.
[tex]\[ \text{Number of Neutrons} = 55 - 25 = 30 \][/tex]
- Therefore, the ion has [tex]\(30\)[/tex] neutrons.

3. Number of Electrons:
- In a neutral atom, the number of electrons is equal to the number of protons. So, a neutral manganese atom would have [tex]\(25\)[/tex] electrons.
- However, since this is a [tex]\(2+\)[/tex] charged ion, it has lost 2 electrons.
[tex]\[ \text{Number of Electrons} = 25 - 2 = 23 \][/tex]
- Therefore, the ion has [tex]\(23\)[/tex] electrons.

Summarizing these details, the ion [tex]\(\ce{^{55}_{25}Mn^{2+}}\)[/tex] has:

- [tex]\(25\)[/tex] protons
- [tex]\(30\)[/tex] neutrons
- [tex]\(23\)[/tex] electrons

Thus, the correct answer from the given options is:
[tex]\(25 p^{+}, 30 n^0, 23 e\)[/tex]