Convert 514 nm to m and express it in scientific notation.

How many atoms are in 1.4 mil of phosphorus trifluoride (pf3)

Which are forms of frozen water? check all that apply. dew frost hail rain sleet

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!