What type of chemical bond shares electrons a. covalent b. ionic

What is the number of moles of chemical units represented by 9.03x10^24? and how do i show work? (dumb it down )

The number to the right of an element's symbol (ex. c-12) identifies the of an isotope.

Which one of the following bonds would you expect to be the most polar? a) b–h b) n–h c) p–h d) al–h e) c–h