It depends on where the radiation is coming from.
Alpha particles are the least penetrating, having the most mass and the most charge. They can be stopped with only a few inches of air or the skin.
Beta particles are middle of the road. They have small mass, and only half the charge of an alpha particle. They can be stopped with a millimeter or so of aluminum, so they have more penetrating power.
Gamma radiation is at the high end. They are photons, with extremely low mass and no charge, so their penetrating power is highest. Often, they require massive shielding to stop them.
So, from outside the body, gamma radiation is the most dangerous.
However, if you ingest the radioactive material into your body, it can lodge in sensitive places, such as the lungs, the thyroid, the bones, nearly anywhere. In that context, alpha particles are the most dangerous, because now they have no barrier to penetration, and they have the most impact on our cells.
Gamma.
gamma decay beta decay alpha decay
gamma
gamma radiation
Gamma rays consist of high-energy waves and always accompanies alpha and beta decay.
The decay product of uranium 238 by alpha disintegration (not beta or gamma) is thorium 234.
gamma decay beta decay alpha decay
There are three types: Beta decay, alpha decay, and gamma decay/gamma rays. They are all dangerous if exposed to a high amount of radioactive matter. When the radioactive isotope undergoes beta, alpha, and gamma decay, there is an emission of a beta particle, alpha particle, and gamma ray (respectively). In highly radioactive matter, there are often trillions of radioactive isotopes that emit these particles and/or rays - and they are very high-energy once emitted. However, they are only dangerous when exposed to a high amount.
alpha decay, beta decay, and gamma radiation
alpha, beta, gamma.
Alpha, beta, and gamma radiation were first observed from a sample of Radium in a magnetic field.
alpha decay, beta decay, and gamma radiation
gamma
Alpha decay decreases the atomic number by two. Beta- decay increases the atomic number by one. Beta+ decay decreases the atomic number by one. Gamma decay does not change the atomic number. However, gamma decay is often incidental to a precipitating alpha or beta event that upsets the energy equilibrium in the nucleus, so the two are not unrelated.
Beta or gamma disintegration.
Alpha, Beta, and Gamma
gamma radiation
Americium-241 has an alpha decay associated with gamma.