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Alpha, beta, and gamma

Research begun by people such as New Zealander Ernest Rutherford soon after the discovery of nuclear radiation indicated that different types of rays are emitted. Eventually, three types were distinguished and named alpha α size 12{ left (α right )} {} , beta β size 12{ left (β right )} {} , and gamma γ size 12{ left (γ right )} {} , because, like x-rays, their identities were initially unknown. [link] shows what happens if the rays are passed through a magnetic field. The γ size 12{γ} {} s are unaffected, while the α size 12{γ} {} s and β size 12{β} {} s are deflected in opposite directions, indicating the α size 12{α} {} s are positive, the β size 12{β} {} s negative, and the γ size 12{γ} {} s uncharged. Rutherford used both magnetic and electric fields to show that α size 12{α} {} s have a positive charge twice the magnitude of an electron, or + 2 q e size 12{+2 lline q rSub { size 8{e} } rline } {} . In the process, he found the α size 12{γ} {} s charge to mass ratio to be several thousand times smaller than the electron’s. Later on, Rutherford collected α size 12{γ} {} s from a radioactive source and passed an electric discharge through them, obtaining the spectrum of recently discovered helium gas. Among many important discoveries made by Rutherford and his collaborators was the proof that α size 12{γ} {} radiation is the emission of a helium nucleus . Rutherford won the Nobel Prize in chemistry in 1908 for his early work. He continued to make important contributions until his death in 1934.

The figure shows north and south poles of a magnet through which three rays labeled as alpha beta and gamma are passed. After passing through a magnetic field the alpha ray is slightly deflected toward the right. The beta ray is deflected toward the left and the gamma ray is not deflected.
Alpha, beta, and gamma rays are passed through a magnetic field on the way to a phosphorescent screen. The α size 12{γ} {} s and β size 12{β} {} s bend in opposite directions, while the γ size 12{γ} {} s are unaffected, indicating a positive charge for α size 12{γ} {} s, negative for β size 12{β} {} s, and neutral for γ size 12{γ} {} s. Consistent results are obtained with electric fields. Collection of the radiation offers further confirmation from the direct measurement of excess charge.

Other researchers had already proved that β size 12{β} {} s are negative and have the same mass and same charge-to-mass ratio as the recently discovered electron. By 1902, it was recognized that β size 12{β} {} radiation is the emission of an electron . Although β size 12{β} {} s are electrons, they do not exist in the nucleus before it decays and are not ejected atomic electrons—the electron is created in the nucleus at the instant of decay.

Since γ size 12{γ} {} s remain unaffected by electric and magnetic fields, it is natural to think they might be photons. Evidence for this grew, but it was not until 1914 that this was proved by Rutherford and collaborators. By scattering γ size 12{γ} {} radiation from a crystal and observing interference, they demonstrated that γ size 12{γ} {} radiation is the emission of a high-energy photon by a nucleus . In fact, γ size 12{γ} {} radiation comes from the de-excitation of a nucleus, just as an x ray comes from the de-excitation of an atom. The names " γ size 12{γ} {} ray" and "x ray" identify the source of the radiation. At the same energy, γ size 12{γ} {} rays and x rays are otherwise identical.

Properties of nuclear radiation
Type of Radiation Range
α size 12{α} {} -Particles A sheet of paper, a few cm of air, fractions of a mm of tissue
β size 12{β} {} -Particles A thin aluminum plate, or tens of cm of tissue
γ size 12{γ} {} Rays Several cm of lead or meters of concrete

Ionization and range

Two of the most important characteristics of α size 12{α} {} , β size 12{β} {} , and γ size 12{γ} {} rays were recognized very early. All three types of nuclear radiation produce ionization in materials, but they penetrate different distances in materials—that is, they have different ranges . Let us examine why they have these characteristics and what are some of the consequences.

Questions & Answers

Describe an experiment to determine short half life
Tyson Reply
what is science
Kenedy Reply
A 20MH coil has a resistance of 50 ohms and us connected in series with a capacitor to a 520MV supply
Musa Reply
what is physics
Caya Reply
it is the science which we used in our daily life
Sujitha
Physics is the branch of science that deals with the study of matter and the interactions it undergoes with energy
Junior
it is branch of science which deals with study of happening in the human life
AMIT
it is when you get up of your arse and do some real work 😁
A 20MH coil has a resistance of 50 ohms and is connected in series with a capacitor to a 250MV supply if the circuit is to resonate at 100KHZ, Determine 1: the capacitance of the capacitor 2: the working voltage of the circuit, given that pie =3.142
Musa
Heat is transfered by thermal contact but if it is transfered by conduction or radiation, is it possible to reach in thermal equilibrium?
Eden Reply
Yes, It is possible by conduction if Surface is Adiabatic
Astronomy
what are the fundamentals qualities
Magret Reply
what is physic3
Kalilu
what is physic
Kalilu
Physics? Is a branch of science dealing with matter in relation to energy.
Moses
Physic... Is a purging medicine, which stimulates evacuation of the bowels.
Moses
are you asking for qualities or quantities?
Noman
give examples of three dimensional frame of reference
Ekwunazor Reply
your fat arse sitting all day is a good reference of three dimensional numbnut
Universe
Noman
Yes the Universe itself
Astronomy
Examine different types of shoes, including sports shoes and thongs. In terms of physics, why are the bottom surfaces designed as they are? What differences will dry and wet conditions make for these surfaces?
Lathan Reply
sports shoes are designed in such a way they are gripped well with your feet and their bases have and high friction surfaces, Thong shoes are for comfort, these are easily removed and light weight. these are usually low friction surfaces but in wet conditions they offer greater friction.
Noman
thong sleepers are usually used in restrooms.
Noman
what is wave
Ochigbo Reply
The phenomenon of transfer of energy
Noman
how does time flow in one dimension
Lord Reply
you mean in three dimensions......numbnut
yeah that was a mistake
Lord
if it flows in three dimensions does it mean if an object theoretically moves beyond the speed of light it won't experience time
Lord
time seems to flow in one direction...but I the past present and future happen every moment time flies regardless.
but if an object moves beyond the speed of light time stops right for it
Lord
yes but at light speed it ceases
Lord
yes it always flow from past to future.
Noman
if v=ktx Ly Mz find the value of x,y and z
Emmanuel Reply
x=v=ktx Ly Mz find the value of x,y and z
y=v=ktx Ly Mz find the value of x,y and z
z=v=ktx Ly Mz find the value of x,y and z
now get your lazy arse up and clean the kitchen 😁
I want to join the conversation
Subaba Reply
😂
hmm
Stephen
what conversation you talking about? .....numbnut
how do i calculate for period of the oscillation
Bridget Reply
T=2π√(m÷k).K is spring constance
Ambe
T=2π√m/k
Lord
does the force in a system result in the energy transfer?
Lebatam Reply
full meaning of GPS system
Anaele Reply
global positioning system
Noman
what's the use of the GPS
Matthew
Practice Key Terms 8

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Source:  OpenStax, College physics. OpenStax CNX. Jul 27, 2015 Download for free at http://legacy.cnx.org/content/col11406/1.9
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