What is homogeneous substance that are evenly mixed

Adilute aqueous potassium nitrate solution is

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 would happen to a volleyball left outside in the winter? o o o o a. it would expand. b. it would lose air. c. it would shrink. d. it would explode.