Matter is classified as a
(1) substance, only
(2) substance or as a mixture of substances
(3) homogenous mixture, only
(4) homogenous mixture or as a heterogeneous mixture

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!