Which of these describes an exothermic reaction?

1. energy is released by the reaction

2. energy is absorbed by the reaction

3. no energy is transferred by the reaction

4. energy is created in the reaction

What is the fate of the electrons that interact with a specimen in an electron microscope?

The transfer of heat through the movement of a gas or liquid a. convection b. conduction c. radiation

Two resistors r1 and r2 may be connected either in series or parallel across an ideal battery with emf ε. we desire the rate of energy dissipation of the parallel combination to be 8.75 times that of the series combination. if r1 = 105 ω, what are the (a) smaller and (b) larger of the two values of r2 that result in that dissipation rate?