If we were dealing with an atom that had a total of 20 electrons in its electron cloud, how many of those electrons would have quantum number LaTeX: n=1?

Question

2
10
4
1

Answer 1

In an atom with 20 electrons, the distribution of electrons among the various energy levels, indicated by the principal quantum number $n$, follows the principle that each energy level can hold a maximum number of electrons. The maximum number of electrons in a given level $n$ is given by the formula $2n^2$.

For $n=1$:

• Maximum number of electrons = $2(1^2)=2$.

Therefore, only 2 electrons can occupy the first energy level (where $n=1$).

So, the answer is 2.