The table shows the amount of radioactive element remaining in a sample over a period of time: What is the half-life of the element in hours?
Group of answer choices
a. 63 hours
b. 7 hours
c. 21 hours
d.14 hours

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

Predict whether the changes in enthalpy, entropy, and free energy will be positive or negative for the boiling of water, and explain your predictions. how does temperature affect the spontaneity of this process?

4786 joules of heat are transferred to a 89.0 gramsample of an unknown material, with an initialtemperature of 23.0°c. what is the specific heat of thematerialif the final temperature is 89.5 °c?