TIME REMAINING 40:27
What must happen before a chemical reaction can begin?
The activation energy must be exceeded.
The activation energy must be reached.
The concentrations of products and reactants must be equal.
The concentration of reactant molecules must be reduced.

What are the characteristics of living things

What evidence supports the law of conservation of energy? a) mechanical energy is converted to chemical energy during photosynthesis. b) oxygen is made from the breakdown of carbon dioxide during photosynthesis. c)energy is absorbed by chlorophyll and becomes chemical energy during photosynthesis. d)the sun gives off light energy that is absorbed by plants.

What is true about all plutons? they form below earth’s surface. they form near earth’s surface. they form above earth’s surface. they cut across other rock layers.