first to answer correctly gets brainleist! (you dont needa hear that vid thingy tahts just for ppl who cant read or need orial commidations or wtv lol)

What is true for a substance that releases energy

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 be the original temperature of a gas that has a volume of 2.0 l and a pressure of 2.0 atm and an unknown temperature that the volume increased to 3.5 l in its pressure decreased to 1.0 atm if the final temperature is measured to be 11°c