How many significant figures are in the following: 10,600

What overall charge must all compounds have

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

If a molecule with a molecular formula of c13h18 is treated with an excess of h2 in the presence of finally divided pt metal under conditions required for maximum hydrogenation of the molecule to give a molecule with a formula c13h24, how many rings are in the molecule?