An atom contains a total of 25 electrons. When the atom is in the ground state, how many different principal energy levels will contain electrons?

Question

An atom contains a total of 25 electrons. When the atom is in the ground state, how many different principal energy levels will contain electrons?

1 Answer

Impact of this question

10613 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-01-18T04:53:13

Well, with $25$ $25$ electrons, whatever atom it is, it need not be neutral... but since it's within the neighborhood of a transition metal, we can assume it's one of them... i.e. it may be $Mn$ $"Mn"$ , or perhaps ${Co}^{2 +}$ $"Co"^(2+)$ .

With $25$ $25$ electrons, we can immediately write the electron configuration. Argon has $18$ $18$ electrons and is the previous noble gas, and thus we use it as the noble gas core.

$1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 3 d^{5} 4 s^{2} \to [A r] 3 d^{5} 4 s^{2}$ $1s^2 2s^2 2p^6 3s^2 3p^6 3d^5 4s^2 -> [Ar] 3d^5 4s^2$

And you can convince yourself that $18 + 5 + 2 = 25$ $18 + 5 + 2 = 25$ electrons total.

This lands us in the first-row transition metals, and so we have involved $n = 1, 2, 3,$ $bb(n = 1, 2, 3, )$ and $n = 4$ $bb(n = 4)$ . Those are the only principal energy levels involved... These contain the following orbitals:

$n = 1$ $n = 1$ : $1 s$ $1s$
$n = 2$ $n = 2$ : $2 s, 2 p$ $2s, 2p$
$n = 3$ $n = 3$ : $3 s, 3 p, 3 d$ $3s, 3p, 3d$
$n = 4$ $n = 4$ : $4 s$ $4s$

We ignore the $4 p, 4 d, 4 f$ $4p, 4d, 4f$ obviously because they are empty.

Science

Math

Humanities

... and beyond

An atom contains a total of 25 electrons. When the atom is in the ground state, how many different principal energy levels will contain electrons?

1 Answer

Related questions

Impact of this question