The half-life of a radioactive material is: A. half the time it takes for all of the radioactive nuclei to decay into radioactive nuclei. B. half the time it takes for all of the radioactive nuclei to decay into their daughter nuclei. C. the time it takes for half of all the radioactive nuclei to decay into radioactive nuclei. D. the time it takes for half of all the radioactive nuclei to decay into their daughter nuclei

6. what does the symbol ah stand for? o one calorie given off by a reaction the specific heat of a substance the heat capacity of a substance the heat of reaction for a chemical reaction

Match the following vocabulary terms to their definitions. 1. amount of energy required to change 1 gram of material from the solid to the liquid state at its melting point 2. a measure of the kinetic energy of the particles of a substance 3. the amount of heat energy required to raise the temperature of 1 gram of liquid water from 14.5°c to 15.5°c 4. amount of energy required to change 1 gram of material from the liquid to the gaseous state at its boiling point 5. the amount of energy required to change 1 gram of a substance 1°c a. temperature b. latent heat of vaporization c. latent heat of fusion d. calorie e. specific heat

Compare and contrast physical changes with chemical changes.