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Flashcards in Electrons and atoms and radiation Deck (91)
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What is the definition of relative atomic mass?

The ratio of the average mass of one atom of an element to one twelfth of the mass of carbon 12


What is the charge of an electron?

1.6X10^-19 coulombs


Define specific charge. How do you find it?

Charge per unit mass of an object. Charge(coulombs) ÷ mass(kg)


What is the unit for specific charge?

Coulombs per kilogram.


What can the strong nuclear force do?

It can over come the repelling force of positive protons in the nucleus of an atom.


What is the force of the strong nuclear force?

0.018 N


What is the range of the strong nuclear force?

3 X 10^-15 meters
3 Femto meters.


When is the strong nuclear force repulsive?

Beneath 0.5 fm


What happens to nucleuses that are bigger than calcium ones?

The strong nuclear force can no longer reach from one side to the other. Thus neutrons have to be added at a larger rate to carry the force from one side to the other.


Explain the B- decay of a carbon atom mass 14, protons 6

It will become a nitrogen atom with a mass of 14 and 7 protons. An electron of mass 0 and charge -1 will be emitted. ( this means the charge on each side will be equal to each other)
In addition an electron anti-neutrino will be emitted. It has a charge and mass of 0, looks like a fancy V and has a bar on top.
Remember the electron comes from the nucleus, not the electron cloud.


Explain the beta+ decay of carbon with a mass of 11 six protons.

It will become a boron atom with a mass of 11 and 5 protons. There will be an electron neutrino.( a fancy V with an e next to it. No mass or charge)
There will be a positron (positive electron) with a plus charge. This is the anti particle. It has no bar as it looks odd.


Explain electron capture with a carbon atom of mass 11 and it has 6 protons

The atom and an electron are on one side with boron 11, 5 and an electron neutrino on the other side.


What is a lepton?

A fundamental particle with a lepton number of one.


What is a hadronn?

They are composed of quarks and are split into two sub groups, baryons and mesons.
They are subject to the strong and weak nuclear forces.


What is a baryon?

They have a baryon number of one and are composed of three quarks.
There always have an integer charge.


What is a meson?

There are a quark and antiquark pair.


What can a quark not do?

Exist in isolation


What type of subatomic particle is the proton?

It a baryon. It is the most stable. All baryons will eventually decay into protons.


What is the quark composition of a proton?

Up, up down. This means a total charge of +1


What is the quark composition of a neutron?

Up, down, down meaning an overall charge of 0


What type of subatomic particle is the neutron?

It is a baryon


What are the three types of quarks?

Up, down and strange


If a meson has a strange quark in it, what type of meson do you have?

A K meson


If there is no strange quark in a meson, what type of meson is it?

π Meson


How is an antiparticle different from its normal particle?

It has the same mass but has opposite quantum numbers.


What is special about a π0 meson?

It is its own anti-particle.


What is the charge of an up quark?

Plus two thirds


What is the charge of a down quark?



Name all the leptons

Electrons, muons and the neutrino version of each. (There is also the tauon but you don't have to know about that)


What are the quantum numbers?

Baryon number, lepton number, charge, strangeness.