Which of the following is NOT an example of a chemical reaction? a. sodium and chlorine forming salt
b. a candle burning forming carbon dioxide
c. a marshmallow releasing carbon when burned
d. ice turning into water

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.

Arectangle has a diagonal 20 inches long that forms angles of 60 and 30 with the sides. find the perimeter of the rectangle. for geometry

Exit what is the density of an object having a mass of 5.0 g and a volume of 45.0 cm3?