The study of the properties of matter and how matter changes

What are the first three quantum numbers for the electrons located in subshell 2s?

Acm ruler with main graduations from 1 to 10 from left to right there are 10 secondary graduations between each of the main graduations there is a line that begins. at the left end of the ruler 10 secondary graduations to the left of the “1 main graduation the right end of the line ends on the eighth secondary graduation to the right of 3 how long is the line

Ineed pls urgent 1-20 in order and fully detail step my step.