A. Nickel (III) oxide breaks down to form solid nickel metal and oxygen gas. How many grams of nickel (III) oxide would I need to form 20.5 g of nickel metal? B. What kind of reaction is this?
Must show work.

8.98 dm3 of hydrogen gas is collected at 38.8 °c. find the volume the gas will occupy at -39.9 °c if the pressure remains constant.

Which metals are called noble metals

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!