29/03/2020Radioactivity(Senior Class Physics Study by Topics) 0Comments by Gate Academy Welcome to your Radioactivity(Senior Class Physics Study by Topics) NAME EMAIL PHONE NUMBER 1. The helium in a child's balloon is composed of Former beta particles. None of these Both of these Alpha-particle remnants of previous radioactive processes.2. A sample of radioactive material is held a certain distance away from a Geiger counter. Which of the following procedures would not affect the counting rate? Waiting a billion years and coming back to test it again Placing a 6-foot-thick iron and concrete wall between the sample and the counter. Reducing the mass of the sample Lowering the temperature of the sample3. At which location or locations was radioactive material floating in the air? Location Y Location Y and Z Location Z Location X4. Over 99% of the mass of an atom is located within the tiny nucleus. True False5. Generally speaking, the larger a nucleus is, the greater its Instability. Neither stability nor instability Stability.6. The small white circles represent: Protons Electrons Alpha particles Neutrons7. The source of the Earth's natural heat is Pressure on the Earth's interior. Radioactive decay in the Earth's core. Solar energy in the form of fossil fuels. Molten-hot lava.8. The half-life of a radioactive substance is INDEPENDENT of All of the above Whether the substance exists in an elementary state or in a compound. The number (if large enough) of atoms in the substance. The temperature of the substance.9. In bubble chambers, charged particles move in spirals because The magnetic field decreases. Of energy dissipation . The electric charge increases. The electric charge decreases.10. In nuclear fusion, atoms of hydrogen are combined under intense heat and pressure to form ? Hydrogen Helium Nitrogen Carbon11. An element emits 1 alpha particle, 1 positron, and 3 beta particles. Its atomic number Increases by 1 Decreases by 1. Decreases by 2. Stays the same.12. Which of the following isotopes is radioactive? Carbon-14 Neither is radioactive in nature. Carbon-12 Both are radioactive.13. Most of the radioactivity we personally encounter comes from Fallout from past and present testing of nuclear weapons. Medical X rays. Nuclear power plants. The natural environment14. When a gamma ray is emitted by a nucleus, the nucleus then has less Energy. Charge. Neither of these Both of these15. Which of the following is the best definition for half-life? Half of the time that it takes for the radioactive atoms to decay Half of the time it takes for half of the radioactive atoms to decay The time it takes for half of the radioactive atoms to decay The time it takes for half of a radioactive atom to decay16. A nucleon is either A neutron or an electron A proton or an electron A positron or an electron. A proton or a neutron17. Carbon dating requires that the object being tested contain Inorganic material. Charcoal. Organic material. Sugar molecules18. The sources of X-rays and gamma rays, respectively, are Both electron clouds. Both the atomic nucleus Electron clouds and the atomic nucleus. The atomic nucleus and electron clouds.19. The half-life of Radium-229 is 4 minutes. What was the original mass (to the nearest 1/100th of a gram) of Ra-229 if .32 g remains after 12 minutes? 18.95 256 2.56 1.8920. Artificially induced radioactive elements generally have Long half-lives. Short half-lives.21. The most harmful radiations are those that Damage living cells Kill living cells Restore living cells22. The radium nucleus here would be called: The parent nucleus The daughter nucleus An alpha particle23. Deuterium and tritium are both Neither of these Both of these Isotopes of the same element. Forms of hydrogen.24. Electric forces within an atomic nucleus tend to Push it apart. Hold it together. Neither of these25. When a nucleus emits a beta particle, its atomic number Remains constant, but its mass number changes. Changes, and so does its mass number. Remains constant, and so does its mass number. Changes, but its mass number remains constant.26 out of 25Time is Up!