Question

what particle has 12 protons and 13 neutrons?
12
mg
24.31
23
v
50.94
11
na
22.99
v - 12
na - 13
mg - 25

Explanation:

Step1: Recall atomic number concept

The atomic number \(Z\) is equal to the number of protons. Here, number of protons \(= 12\). From the periodic table, the element with atomic number \(Z = 12\) is \(Mg\) (magnesium).

Step2: Calculate mass number

The mass number \(A\) is given by \(A=\text{Number of protons}+\text{Number of neutrons}\). Substituting the values: \(A=12 + 13=25\). The notation for an isotope is \(^{A}\text{Element}\), so it is \(Mg - 25\).

Answer:

\(Mg-25\)