In terms of energy, how would you classify the following chemical reaction? . 2cu + o2 2cuo + 315 kj. a] endothermic. b] exothermic. c] both endothermic and exothermic. d] neither endothermic nor exothermic

Which of the following signs of a chemical reaction are observed in the reaction of potassium with water? precipitate formed temperature change smell produced gas produced color change

Which sentence about particles in matter is true? a. atoms are present in solids and liquids but not in gases. b. the particles of matter are in constant motion. c. the same kinds of atoms are found in different elements. d. when a solid changes to a liquid, the sizes of the particles change.

How many liters of oxygen gas, at standard temperature and pressure, will react with 35.8 grams of iron metal? 4 fe (s) + 3 o₂ (g) → 2 fe₂o₃ (s)