What is a magnet?(2 points) O A tool used to help determine if certain materials are magnetic
O A tool used to help determine if certain materials have a large mass
O A tool used to help determine if materials are the color blue
O A tool used to help determine if materials use the force of gravity

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!