A material has volume 4.52m^3 and density 8.61kg/m^3. the mass of this material in scientific notation is 3.89 X 10^2 g is it true or false?

Agas is contained in a thick walled balloon when the pressure changes from 1.21 atm to 2.52 the volume changes from 3.75 l to 1.72 l and the temperature change from 293k to blank k

What is the molar mass of potassium nitrate, kno3

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!