Which of the following statements is true about an experiment? the control should be changed by the scientist. the independent variable is the factor changed by the scientist. multiple variables should be changed by the scientist in one experiment. the independent variable is used as a standard for comparison.

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!