How are transverse, longitudinal, and surface waves similar?

I'm learning about the periodic tables and what each subject's configuration is. for example, hydrogen is 1s^1, but i don't understand how you get that. can someone me understand how to figure out how to figure this out? sorry if the question makes no sense, but it would really a lot if you could me understand! you so much if you can!

What is the number of neutrons in an atom with atomic mass of 35

Name 3 types of energy you see being used as you look around a classroom