students must design a device that uses 25 grams of reactant 1 and produces the maximum amount of heat with the smallest amount of reactant 2. How much of reactant 2 should they use to meet the criteria of the sesign challenge?

Which of the following is the main purpose of a human community?

8) animals respond in various ways to stimuli detected through their senses. some of these responses are stimulated by the presence of danger. which of these animal responses is the best example of a response to an immediate threat? a) a rooster crows every morning at the first sign of light. b) as something approaches an octopus, it shoots a cloud of ink. c) from late fall until spring, bears hibernate to preserve energy. d) a dog is getting hot in the sunlight, so he moves to a shaded area.

Identify the structures ! 20 points