Which two observations are evidence that a chemical change is happening? A. A yellow liquid forms as a yellow solid is slowly heated.
I B. Bubbles of gas are released when a solid is combined with a
liquid.
I c. Solid crystals form as the temperature of a liquid is lowered.
D. Light and heat are given off after a spark ignites a substance,

Dwayne filled a small balloon with air at 298.5 k. he put the balloon into a bucket of water, and the water level in the bucket increased by 0.54 liter. if dwayne puts the balloon into a bucket of ice water at 273.15 k and waits for the air inside the balloon come to the same temperature, what will the volume of the balloon be? assume the pressure inside the balloon doesn’t change. type the correct answer in the box. express your answer to the correct number of significant figures. the volume of the balloon at 273.15 k is liters.

Drag each label to the correct location on the chart. classify each reaction as endothermic or exothermic.

Which is true concerning the products and reactants of photosynthesis and cellular respiration? a. the products of photosynthesis are sugars and the reactants of cellular respiration are starches. b. the products of photosynthesis are reactants in cellular respiration. c. oxygen is needed for photosynthesis and is given off in cellular respiration.