When 21.44 moles of Si react with 17.62 moles of N2

3 Si + 2 ⟶ Si3N4

How much of the excess reactant remains after the reaction?

Which of the following might a chemist choose to study? a. glacier movement in alaska b. better ways to recycle plastics c. the effects of hurricanes on turtle populations d. the vibrations in bridges caused by big trucks

What determines the average kinetic energy of the particles in a gas? a. the number of collisions b. the number of particles c. the size of the particles d. the temperature

Which property of a rock remains unchanged by mechanical weathering? a. total surface area b. size and shape c. mineral composition d. sharpness