A balloon is fitted over the open end of a glass beaker that contains water. the beaker is placed over a flame, which heats the water. At the same time, the balloon is squeezed, so that it deflates. What are the correct signs for the heat and work changes to the beaker and balloon system ?

Which statements best describe medical uses for radioactive isotopes? check all that apply. radioactive isotopes are used to detect medical problems. high-energy gamma rays are injected into the body. radioactive isotopes are used to treat some diseases. radiation is used to kill cancer cells. radioactive isotopes are directed at tumors from outside the body.