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.