Plz help for braniliest

Subduction zones occur on earth where dense oceanic crust dives under more buoyant continental crust. these boundaries are characterized by a deep ocean trench next to a high continental mountain range, large numbers of earthquakes and volcanoes. all of this is further evidence for the a) big bang theory b) origin of the species eliminate c theory of plate tectonics d theory of natural selection 4 sedimentary rocks found high in the himalayen mountain

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 solution is considered basic, then a) the hydroxide ion and hydronium ion concentrations are equal. b) the hydroxide ion concentration is less than the hydronium ion concentration. c) the hydronium ion concentration is greater than the hydroxide ion concentration. d) the hydroxide ion concentration is greater than the hydronium ion concentration.