Test On Chapter 25 Nuclear Chemistry Vocabulary Review 10/4/10

The half-life of a radioisotope is the time it takes for half of the nuclei in a sample to decay into products. It is a measure of the stability and radioactive decay rate of the isotope. The answer, "half-life," directly relates to the given statement as it represents the time required for one half of the nuclei to decay. The other options, "scintillation counter" and "fission," are not related to the concept of half-life.

Fusion is the correct answer because it refers to the reaction in which two light nuclei combine to form a nucleus of greater mass. This process releases a large amount of energy and is the same process that powers the sun and other stars. In contrast, fission is the process in which a heavy nucleus splits into two or more lighter nuclei, releasing energy. "Fassion" is not a recognized term in the context of nuclear reactions.

A scintillation counter is a device that uses a coated phosphor surface to detect ionizing radiation. When radiation interacts with the phosphor coating, it produces flashes of light called scintillations. These scintillations are then converted into electrical signals that can be measured and analyzed. This makes scintillation counters useful in various applications such as radiation detection, medical imaging, and environmental monitoring. Unlike a Geiger counter, which detects radiation through ionization, a scintillation counter relies on the emission of light. Therefore, the scintillation counter is the correct answer in this context.

Fission refers to the splitting of an atomic nucleus into smaller fragments. This process releases a large amount of energy and is the basis for nuclear power and atomic bombs. Fission occurs when a heavy nucleus, such as uranium or plutonium, absorbs a neutron and becomes unstable. It then splits into two or more smaller nuclei, releasing additional neutrons and a significant amount of energy. This process can be sustained in a controlled manner in nuclear reactors or can occur explosively in a nuclear bomb.

Radioisotopes are isotopes of an element that have unstable nuclei, meaning that they have an imbalance of protons and neutrons. Due to this instability, they undergo radioactive decay, which involves the release of radiation in the form of particles or electromagnetic waves. This radiation can include alpha particles, beta particles, and gamma rays. Therefore, the correct answer in this case is "radioisotopes," as they are the isotopes that have unstable nuclei and undergo radioactive decay, leading to the emission of radiation.

Alpha particles are positively charged particles consisting of two protons and two neutrons. They are relatively large and heavy compared to other particles, such as beta and gamma particles. Due to their size and charge, alpha particles have low penetrating power and can be easily stopped by a sheet of paper or a few centimeters of air. They are commonly emitted during radioactive decay and can cause ionization and damage to living tissues if they come into contact with them.

Transmutation refers to the process of converting an atom of one element into an atom of another element. This can occur through various methods such as nuclear reactions or radioactive decay. It involves the alteration of the atomic nucleus, resulting in the formation of a different element with a different number of protons. Transmutation is a fundamental concept in nuclear physics and has important applications in fields such as medicine and energy production.

Transuranium elements are elements in the periodic table with atomic numbers above 92. These elements are synthetic and are not naturally occurring. They are created through nuclear reactions and have atomic numbers higher than that of uranium. Examples of transuranium elements include plutonium, americium, and curium. These elements are highly unstable and undergo radioactive decay.

A gamma ray is a high-energy photon that has no mass or electrical charge. This makes it different from alpha and beta particles, which are charged particles. Gamma rays are produced during radioactive decay or nuclear reactions and have the ability to penetrate matter easily due to their high energy. They are commonly used in medical imaging and radiation therapy due to their ability to pass through the body and provide detailed images or target cancer cells.

A Geiger counter is a gas-filled metal tube used to detect the presence of radiation. It works by measuring the ionizing radiation in the surrounding environment. When radiation enters the tube, it ionizes the gas inside, creating an electric current. This current is then amplified and counted, providing a measure of the radiation level. Geiger counters are commonly used in various fields, including medicine, research, and nuclear power plants, to monitor and detect radiation.

Beta particles are high-energy, high-speed electrons or positrons emitted by certain types of radioactive nuclei such as potassium-40. Unlike alpha particles, which are made up of helium nuclei, beta particles are much smaller and have a negative charge. They are able to penetrate further into matter and can be stopped by a few millimeters of aluminum. Gamma rays, on the other hand, are electromagnetic radiation and have no mass or charge. They are more penetrating than both alpha and beta particles and require several centimeters of lead or a few meters of concrete to stop them.

Radiation refers to the emission of energy as electromagnetic waves or as moving subatomic particles, such as alpha or beta particles. In this context, fast-moving electrons released by a radioactive nucleus are considered beta particles, which are a form of radiation. Therefore, the correct answer is radiation.