Radioactive Decay

To fully explain radioactive decay you need quantum mechanics.

The alpha decay of americium-241 produce neptunium-237.

A radioactive substance emit nuclear radiations.

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The neptunium decay series is finished with the stable isotope thallium-205.

Americium-241 has an alpha decay associated with gamma.

• alpha decay - fully ionized helium nuclei
• beta decay - electrons or positrons, and electron neutrinos
• gamma decay - very high energy photons

The half life of americium-241 is 432,2(7) years.

A half life of o,145 s has the isotope polonium-216.

Radiocarbon dating is used to date very recent artifacts, and is usually useful only for archeological purposes. It cannot be used to date rocks, both because of its short half life (about 5,000 years), and because it can only be used to date the remains of living things (such as bones, or wood).

Rocks are dated using other methods, such as Uranium-Lead dating, which has a much longer half life (over 700 million years).

Beta particles (electrons) are less massive than alpha particles (Helium-4 nuclei), by a factor of approximately 8000.

Beta+ decay and electron capture causes the atomic number to drop by one. Beta- causes the the atomic number to rise by one.
Proton emission causes the atomic and mass number to drop by one.
Neutron emission causes the mass number to drop by one.
Alpha decay causes the atomic number to drop by two and the mass number to drop by four.

Beta particles or radiation is an electron emitted at high speed or energy from some types of unstable elements in a process known as beta-decay.

Beta radiation is not healthy for living things. It is usually stopped by a few millimeters of metal, wood, or plastic. Direct exposure to the skin can cause radiation burns.

Nuclear radiation is neither good nor bad, it is a natural phenomenon. Natural phenomena cannot be good or bad (this is an ethical/moral judgement), they are simply facts.

It involves determining the age of an ancient fossil or specimen by measuring its carbon-14 content. Carbon-14, or radiocarbon, is a naturally occurring radioactive isotope that forms when cosmic rays in the upper atmosphere strike nitrogen molecules, which then oxidize to become carbon dioxide.

No, there are no detectable levels of carbon-14 left in any sample older than roughly 40,000 years. Without carbon-14 in the sample, no date can be determined.

Matter can be made to undergo nuclear decay in reactors, but it is a process that occurs spontaneously in nature.

You can't just start or stop radioactive decay. A certain type of atom (a certain isotope) will basically ALWAYS decay at a certain rate. The statement might refer to what happens at time t = 0, i.e., before the material had time to decay.

Massive nuclei are unable to remain bound aganst the repulsive force of their protons, which all have positive charge. This also occurs with elements #43 (technetium) and #61 (promethium) which because of their particular nuclear geometry are inherently unstable and radioactive, with the only natural isotopes having half-lives of just over 2 years.

Yes. Alpha particles can be a product of radioactive decay, and alpha particles are simply Helium nuclei. Unless they interact with other atoms, they will tend to pick up stray electrons (they need two) and become stable 4He atoms.

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It can be alloyed with beryllium to provide a source of neutrons. It can eliminate static charges in textile mills. It is used on brushes to clean film, and can provide thermoelectric power in space satellites. Of course, it can also be used as a poison, as it is over 250,000 times as toxic as cyanide, and is very hard to find in a body.

Alpha emission means that an alpha particle (2 protons + 2 neutrons) are emitted, so the original nucleus has 2 protons and 2 neutrons more.