what are alpha particles?

Question

we know that when any radioactive substance spontaneously disintigrates it emits alpha particles,beta particles,gamma radiation . why they are emiting and what abt them?

Answer 1

Alpha particle
From Wikipedia, the free encyclopedia
Jump to: navigation, search
An alpha particle is deflected by a magnetic field Alpha radiation consists of helium-4 nuclei and is readily stopped by a sheet of paper. Beta radiation, consisting of electrons, is halted by an aluminium plate. Gamma radiation is eventually absorbed as it penetrates a dense material.Alpha particles (named after the first letter in the Greek alphabet, α) are a highly ionizing form of particle radiation which have low penetration. They consist of two protons and two neutrons bound together into a particle identical to a helium nucleus; hence, it can be written as He2+.

Alpha particles are emitted by radioactive nuclei such as uranium or radium in a process known as alpha decay. This sometimes leaves the nucleus in an excited state, with the emission of a gamma ray removing the excess energy. In contrast to beta decay, alpha decay is mediated by the strong nuclear force. Classically, alpha particles do not have enough energy to escape the potential of the nucleus. However, the quantum tunnelling effect allows them to escape.

When an alpha particle is emitted, the atomic mass of an element goes down by roughly 4 amu, due to the loss of 4 nucleons. The atomic number of the atom goes down by 2, as the atom loses 2 protons, becoming a new element. An example of this is when radium becomes radon gas due to alpha decay.

hope this helps u.read the rest of it in this site :

www.en.wikipedia.org/wiki/Alpha_particle

Answer 2

Definition Of Alpha Particle

Answer 3

A radioactive substance is unstable, because the atoms that make it up are in a state that cannot be maintained. Hence, the atom starts changing to reach a stable state.

Some substances are 'too heavy', meaning that the attraction of the gravity and the repulsion of the electromagnetic charge between the protons is out of balance. This causes a 'strong nuclear force' between the quarks that make up the nucleons, and as a result, a particle consisting of two neutrons and two protons is emitted. Since they have two protons, they have a strong positive charge, and ionise other particles in the air. This saps their energy quickly, and means that they cannot travel very far. In fact, to escape the nucleus, they 'borrow' energy from their future self through a process called quantum tunnelling, which relies on the wave-like properties of the alpha particle.

We take advantage of this property in smoke detectors. One part of the machine releases an alpha particle, and another part detects it. If smoke enters the machine, it prevents the alpha particle from reaching the detector, and triggers the alarm.

Beta particles are emitted by particles that have too many neutrons, and not enough protons - there is too much gravity, and not enough electromagnetic charge. This means that the 'weak nuclear force' causes a neutron to turn into a proton and an electron (and also an antineutrino). Beta particles are less likely to ionise, and therefore can travel further (a few metres) than alpha particles. As a result, they are used to test the thickness of items, such as paper.

During any process of radioactive decay, there may still be too much energy in the atom for it to remain stable. That extra energy is released in the form of 'Gamma rays'. These are extremely high energy, and because they are waves, they have no mass and no charge. That means they can travel much further. They are identical to x-rays, except that they are produced by nuclear radiation instead of electromagnetic radiation.

Answer 4

Radioactive substances are unstable one and by continuous emission of alpha,beta and gamma they become stable one. There is the rule of nature that every thing moves toward stability.Thats why the substances emitting these particles.
Alpha and beta are the particles whereas Gamma is the radiation.
Alpha particle is the helium nuclei with atomic number 4 and beta particle is the electron with one negative charge.

Answer 5

The first three types of radiation discovered were called alpha, beta, and gamma after the first three letters of the greek alphabet. It turns out that an alpha is just 2 protons and 2 nueutrons stuck together (this is also a helium nuclues), a beta is just an electron, and a gamma is just energy, a gamma ray on the far end of the electromagnetic spectrum.
Atoms emit these three because they are unstable, have too much energy and decay.

Answer 6

An alpha particle is a helium nucleus (two protons and two neutrons).

Beta particles are electrons.

Gamma rays are intense X-rays.

Answer 7

Alpha particles are helium nucleus.

Answer 8

An alpha particle is a helium nucleus (two protons and two neutrons).

Answer 9

Alpha particles are basically helium nuclei

Answer 10

Alpha particals are helium nuclei beta particals are electrons and gamma particals are energy.