What does the area between points D and E represent for the substance on the heating curve below? A freezing point
B melting point
C boiling point
D sublimation point

What layer of the atmosphere is directly above the troposphere?

Which statement is true about a catalyst? a: a catalyst decreases the rate of the reaction. b. a catalyst is consumed during a chemical reaction. c. a catalyst lowers the activation energy of a reaction. d. a catalyst increases the reactant concentration during a reaction.

Rays from the sun are not considered matter true or false