1.
What type of radiation does a radon emmit?
Correct Answer
B. AlpHa particles
Explanation
Radon emits alpha particles. Alpha particles are made up of two protons and two neutrons, which are essentially helium nuclei. They have a positive charge and are relatively large and heavy. This type of radiation is commonly emitted by radioactive elements like radon during the process of radioactive decay. Alpha particles have low penetrating power and can be stopped by a sheet of paper or a few centimeters of air.
2.
Hoiw do scientists express the decay rates of radioactive isotopes?
Correct Answer
C. Half-life
Explanation
Scientists express the decay rates of radioactive isotopes using the concept of half-life. The half-life is the time it takes for half of the radioactive atoms in a sample to decay. It is a measure of the stability or instability of an isotope. By knowing the half-life, scientists can determine the rate at which a radioactive isotope decays and make predictions about its behavior over time.
3.
What determines the type of decay a radioisotope will undergo?
Correct Answer
D. The neutron - to- proton ratio
Explanation
The neutron-to-proton ratio determines the type of decay a radioisotope will undergo. This ratio is crucial because it affects the stability of the nucleus. If the ratio is too high or too low, the nucleus may become unstable and undergo radioactive decay to achieve a more stable state. Different types of decay, such as alpha decay, beta decay, or gamma decay, occur depending on the specific neutron-to-proton ratio of the radioisotope.
4.
How much of a sample of radioisotope remains after one half-life?
Correct Answer
B. 50% of the csample remains after one half-life
Explanation
After one half-life, half of the sample of radioisotope remains. This is because during each half-life, half of the radioactive atoms decay and transform into stable atoms. Therefore, the remaining sample would be 50% of the original amount.
5.
How much of a sample of radioisotope remains after two half - lives ?
Correct Answer
A. 25% of the csample remains after one half-life
Explanation
After one half-life, 50% of the sample of radioisotope remains. Therefore, if 25% of the sample remains after one half-life, it means that the sample has gone through two half-lives.
6.
What are two ways that transmutation can occur?
Correct Answer
C. Radioactive decay and particle bombardment of a nucleus
Explanation
Transmutation can occur through radioactive decay, which involves the spontaneous breakdown of an unstable atomic nucleus, resulting in the emission of radiation. Additionally, transmutation can also occur through particle bombardment of a nucleus, where high-energy particles are directed at an atomic nucleus, causing it to undergo a change in its composition or properties. Both of these processes can lead to the conversion of one element into another, hence facilitating transmutation.
7.
A radioisotope has a half-life of 4 days. How much of a 20-gram sample of this radioisotope remains at the end of each time period?4days and 8 days
Correct Answer
C. 10g and 5g
Explanation
The half-life of a radioisotope is the time it takes for half of the sample to decay. In this case, the half-life is 4 days. After 4 days, half of the 20-gram sample, which is 10 grams, remains. After another 4 days (a total of 8 days), half of the remaining 10 grams, which is 5 grams, remains. Therefore, at the end of each time period, 10 grams and 5 grams of the sample remain.
8.
The mass of cobalt -60 in a sample is found to have decreasef from 0.800 to 0.200g ina period of 10.5 years. From this information, calculate the half-life of cobalt-60.
Correct Answer
B. 5.25 years
Explanation
The half-life of a radioactive substance is the time it takes for half of the initial amount of the substance to decay. In this case, the mass of cobalt-60 decreased from 0.800g to 0.200g in a period of 10.5 years. This means that it took 10.5 years for half of the initial mass (0.800g) to decay to 0.400g. Therefore, the half-life of cobalt-60 is 10.5 years.
9.
What is the general meaning of fission?
Correct Answer
A. An object splint into smaller parts.
Explanation
Fission refers to the process in which an object or nucleus splits into smaller parts. This can occur in various contexts, such as nuclear fission where the nucleus of an atom splits into two smaller nuclei, or in biology where cells divide into smaller cells through cell fission. In both cases, the general meaning of fission is the splitting or division of an object into smaller parts.
10.
What is the general meaning of fusion?
Correct Answer
C. Objects combine into a larger whole.
Explanation
Fusion refers to the process of combining two or more objects or entities into a larger whole. It implies the merging or blending of separate elements to create a unified entity. This can be seen in various contexts, such as in physics where fusion refers to the combining of atomic nuclei to release energy, or in cooking where ingredients are mixed together to create a new dish. In all cases, fusion involves the coming together of separate parts to form a larger and more cohesive whole.
11.
How is the energy of the sun produced?
Correct Answer
A. Energy is increased during the formation of helium nuclei.
Explanation
During the formation of helium nuclei, energy is released. This is because the process of nuclear fusion, which occurs in the core of the sun, involves the fusion of hydrogen nuclei to form helium nuclei. This fusion reaction releases a tremendous amount of energy in the form of light and heat. This energy is what powers the sun and allows it to emit heat and light, providing energy to sustain life on Earth.
12.
What happens in a nuclear chain reaction?
Correct Answer
A. Neutrons produce by fissionable atoms, producing more neutrons that react with other fissionable atoms.
Explanation
In a nuclear chain reaction, neutrons are produced by fissionable atoms. These neutrons then go on to react with other fissionable atoms, causing them to undergo fission and release more neutrons. This process continues in a chain reaction, with each fission event producing more neutrons that go on to cause further fission reactions. This chain reaction releases a large amount of energy and is the basis for nuclear power and nuclear weapons.
13.
Why are spent fuel rods from a nuclear reaction stored in water?
Correct Answer
B. Water warms spent fuel rods and provides a radiation shield.
14.
___________reaction involves splitting nuclei.
Correct Answer
B. Fission
Explanation
Fission is the correct answer because it involves the splitting of nuclei. In nuclear fission, the nucleus of an atom is divided into two or more smaller nuclei, releasing a large amount of energy. This process is commonly used in nuclear power plants and atomic bombs. Fusion, on the other hand, is the process of combining two or more atomic nuclei to form a larger nucleus, which releases an even greater amount of energy.
15.
In _________________ reactions, small nuclei combines and release much more energy.
Correct Answer
A. Fusion
Explanation
Fusion reactions involve the combination of small nuclei to form larger nuclei, releasing a significant amount of energy in the process. This is because the binding energy per nucleon increases as the nuclei combine, leading to a release of energy. In contrast, fission reactions involve the splitting of large nuclei into smaller ones, and while energy is also released in fission reactions, fusion reactions generally release much more energy due to the higher binding energy per nucleon in the resulting nuclei.
16.
What does nuclear moderation accomplish in a nuclear reactor?
Correct Answer
A. Slows down neutrons
Explanation
Nuclear moderation in a nuclear reactor slows down neutrons. This is important because fast neutrons are less likely to cause fission reactions in the reactor's fuel. By slowing down the neutrons, the likelihood of fission reactions increases, allowing for a sustained nuclear chain reaction. Slowing down the neutrons also helps to control the rate of the reaction and prevent overheating or runaway reactions.
17.
What is the source of the radioactive nuclei present in spent fuel rods?
Correct Answer
B. Unused nuclear fuel and fission products
Explanation
The source of the radioactive nuclei present in spent fuel rods is unused nuclear fuel and fission products.
18.
What are some advantanges to using a fusion reactor to produce electricity?
Correct Answer
A. Potenial fuels are inexpensensive and readly available
Explanation
Using a fusion reactor to produce electricity has the advantage of potential fuels being inexpensive and readily available. This means that the cost of fuel for the reactor would be low and there would be no shortage of fuel supply. This makes fusion reactors a more sustainable and cost-effective option for generating electricity compared to other forms of energy production.
19.
Geiger counter, scintillation counter, and film badge
Correct Answer
C. Methods of detecting radiation
Explanation
The Geiger counter, scintillation counter, and film badge are all methods used to detect radiation. A Geiger counter detects radiation by measuring the ionization produced in a gas by radiation, while a scintillation counter detects radiation by measuring the light produced when radiation interacts with a scintillating material. A film badge, on the other hand, is a personal dosimeter that uses photographic film to detect and measure radiation exposure. These methods are commonly used in various fields to monitor and measure levels of radiation for safety purposes.
20.
________________ and ______________are applications of radioisotopes in medcine.
Correct Answer
C. Medical diagnosis and treatment of disease
Explanation
Radioisotopes are widely used in medicine for both diagnosis and treatment of diseases. In medical diagnosis, radioisotopes are used to create images of internal organs and tissues, allowing doctors to detect and diagnose various conditions. This technique is known as nuclear imaging or scintigraphy. In the treatment of diseases, radioisotopes are used in radiation therapy to target and destroy cancer cells. This is done through a process called radiotherapy, which helps in shrinking tumors and preventing the spread of cancer. Therefore, medical diagnosis and treatment of diseases are the correct applications of radioisotopes in medicine.
21.
If you work regularly near a radiation source, why might your employer want to monitor your exposure to radiation by having you use a film badge rather thana Geiger counter?
Correct Answer
B. It monitors the degree and type of exposture to all types of radiation for an individual.
Explanation
The employer would want to monitor the exposure to radiation for an individual using a film badge rather than a Geiger counter because a film badge provides a more accurate and comprehensive measurement of the degree and type of exposure to all types of radiation. Unlike a Geiger counter, which only detects and measures the presence of radiation, a film badge records the radiation dose received over a period of time. This allows for a more thorough assessment of the individual's overall exposure to radiation.
22.
What is an advantage of using a radioactive seed, consiisting of a radioisotope in a small gold tube, to treat a cancerous tumor?
Correct Answer
C. The seeds emit beta particles and gamma rays to kill the surrounding cancer cells. The seed cannot move from its inserted location.
Explanation
The advantage of using a radioactive seed, consisting of a radioisotope in a small gold tube, to treat a cancerous tumor is that the seeds emit beta particles and gamma rays to kill the surrounding cancer cells. Additionally, the seed cannot move from its inserted location, ensuring targeted and localized treatment.
23.
Two medical uses of radioactive isotopes are ______________ and __________________.
Correct Answer
C. Tracers in disease diagnosis and treatment of cancer
Explanation
Radioactive isotopes can be used as tracers in disease diagnosis to track the movement of substances within the body and identify any abnormalities. They can also be used in the treatment of cancer, where radiation therapy is used to target and destroy cancer cells.