What were there problems identified by George washingston carver

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

Which type of substance ionizes partially and gives off hydrogen ions when dissolved in water? a. strong acid b. strong base c. weak acid d. weak base

Calculate the mass of 0.750 mol of the following substance. na3po4. , i'm not quite sure on how to set up the problem to solve! : (