Are the bond polarities of SiH4 polar or non polar ?

Note the ph and poh values labeled with letters on the ph scale below. based on log rules and the way ph is calculated, what is the difference in [oh– ] concentration between point a and point b. a) 10^1 b) 10^5 c) 10^6 d) 10^7

Seawater contains approximately 3.5%nacl by mass and has a density of 1.02 g/ml. what volume of seawater contains 7.5 g of sodium?

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!