What is the smallest unit retaining properties of element?

What is driving behind plate tectonics (plate movment)? a) gravity only b) inertia c) convection and gravity d) the sun theres no option for science so i picked chemistry. plz

Which of these sequences lists the correct order for the creation of sedimentary rock from sediment? a. deposition, burial, compaction, cementation b. burial, deposition, compaction, cementation c. compaction, deposition, burial, cementation d. cementation, deposition, burial, compaction

When hydrochloric acid reacts with potassium hydroxide solution, the following reaction occurs. hcl (aq) + koh (aq) h2o (l) + kcl (aq) the reaction gives off heat energy, so it is an reaction.