A box is pushed with a force of 30N while 5 N of friction acts in the opposite direction The box accelerates at 1.7 m/s2. What is the mass of the box???

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!