Experiments have determined that the average mass of helium is 4.0026 amu. What is the mass defect for the helium atom?

Iodine-131 is a radioactive material. It contains 53 protons and 78 neutrons. During the process of Iodine131 decay, one of its 78 neutrons becomes a proton and an electron is formed in the process. Based on this information select all that apply. -The mass number is unchanged by the decay of Iodine-131 .-The mass number is changed by the decay of Iodine-131.-After decay the atom is still Iodine.-After decay the atom is not Iodine.

Positron emission by Co-55 produces an isotope with what atomic number?

Negatively charged particles of radiation emitted from the decay of radioactive substances are known as   A) protons B) alpha particles C) beta particles D) neutrons E) gamma rays

Radioactive nuclides can decay through the release of several differ- ent types of radiation. ● D List the three basic types of radiation in order from most penetrating to least penetrating. Describe what happens to the mass number and the atomic number of a nuclide during alpha decay. Answer in complete sentences.

a. 27 x 106 kJ   b. 2.68 x 106 kJ                 c. 3.10 x 106 kJ                   d. 3.15 x 106 kJ e. 7.37 x 108 kJ