Help this is 3dg3nuity Lab acids and Bases

Calculate the molar mass of aluminum oxide (al2o3). express your answer to four significant figures.

What does the symbol (–hfus) indicate in a phase change?

Which of the following statements is true? a. most heat energy is easily recovered and used for useful actions. b. friction causes molecules to vibrate more slowly. burning air and gasoline in an c. engine changes chemical energy into mechanical energy. it is impossible to d. change mechanical energy into mechanical energy.