6) How many moles would be in 25 grams of NaCl?

You have a sample of a gas that occupies a volume of 17ml at -111 degrees celsius. what volume does the sample occupy at 88 degrees celsius? show all work asap

How many moles is 14.5 cm^3 of platinum? the density of platinum is 21.45 g/cm^3.

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!