Question

an atomic cation with a charge of +1 has the following electron configuration: ne 3s² what is the chemical symbol for the ion? how many electrons does the ion have? how many 3s electrons are in the ion?

Explanation:

Step1: Determine the number of electrons in the ion

• The electron configuration \([Ne]3s^{2}\) is given.
• \(Ne\) has \(10\) electrons. The \(3s^{2}\) sub - shell has \(2\) electrons.
• So the total number of electrons in the ion \(n = 10 + 2=12\)

Step2: Find the chemical symbol of the ion

• The ion has a charge of \(+ 1\). Let the number of protons in the atom (before ionization) be \(p\).
• Using the formula \(q=p - n\) (where \(q\) is the charge of the ion, \(p\) is the number of protons, and \(n\) is the number of electrons in the ion). Given \(q = + 1\) and \(n=12\), then \(1=p - 12\), so \(p = 13\).
• The element with \(p = 13\) is aluminium. The ion is \(Al^{+}\)

Step3: Count the number of \(3s\) electrons

• From the electron configuration \([Ne]3s^{2}\), the number of \(3s\) electrons is \(2\)

Answer:

• Chemical symbol for the ion: \(Al^{+}\)
• Number of electrons in the ion: \(12\)
• Number of \(3s\) electrons in the ion: \(2\)