Which Ray has most penetrating power?
A sheet of paper is all that is needed for the absorption of alpha rays. However, it may take a material with a greater thickness and density to stop beta particles. Gamma rays have the most penetrating powers of all three radiation sources.
The penetrating power of alpha rays, beta rays, and gamma rays varies greatly. Alpha particles can be blocked by a few pieces of paper. Beta particles pass through paper but are stopped by aluminum foil. Gamma rays are the most difficult to stop and require concrete, lead, or other heavy shielding to block them.
- There are three types of nuclear radiation: alpha, beta and gamma. Alpha is the least penetrating, while gamma is the most penetrating. Nonetheless, all three are ionising radiation: they can knock electrons out of atoms and form charged particles.
- The alpha particle is a helium nucleus; it consists of two protons and two neutrons. It contains no electrons to balance the two positively charged protons. Alpha particles are therefore positively charged particles moving at high speeds. Beta particles are emitted by neutron rich unstable nuclei.
- Alpha and beta rays are composed of discrete subatomic particles. This is part of the reason why these rays are more easily deflected by less dense matter. Gamma rays are on a whole different level. They are pure energy and radiation so only the most dense kind of matter can deflect it.
Occurs when an unstable nucleus emits a particle composed of two protons and two neutrons. Thus the symbol for alpha radiation is the symbol for helium-4. Most massive of all particles emitted by radioactive nuclei. Alpha radiation has the highest ionizing power and the lowest penetrating power.
- Radioactive tracers are used to investigate a patient's body without the need for surgery. Gamma emitters and sometimes beta emitters are used. This is because gamma rays and beta particles can pass through skin, whereas alpha particles cannot. Nuclear radiation can damage cells.
- Alpha is stopped by the MASS of the atoms. Gamma radiation is not charged, since it is just a photon. And because gamma rays are the most penetrating of the radiations. Gamma rays are highly energetic waves and are poor at ionizing other atoms or molecules.
- Each particle contains a pair of neutrons and a pair of protons. They don't penetrate very deeply into the skin, if at all -- in fact, clothing can stop alpha particles. Unfortunately, alpha particles can be inhaled or ingested, usually in the form of radon gas. Once ingested, alpha particles can be very dangerous.
Gamma rays are the most penetrating of the radiations. Gamma rays are highly energetic waves and are poor at ionising other atoms or molecules. It cannot be said that a particular thickness of a material can absorb all gamma radiation.
- Alpha particles are made of 2 protons and 2 neutrons. We can write them as , or, because they're the same as a helium nucleus, . They have a low penetrating power - you can stop them with just a sheet of paper. Because they have a large charge, alpha particles ionise other atoms strongly.
- Alpha particles can be stopped by a sheet of paper, beta particles by aluminum, and gamma radiation by a block of lead.
- The Detection of Ionizing Radiation. Various instruments and devices are used for the detection of radiations. The best known device is the Geiger-Muller counter. This device consists of two parts, a detecting tube and a counter.
Updated: 2nd October 2019