Particles Flashcards
What are the three constituents of an atom? (3)
Proton, Neutron, Electron
What is the relative mass of a Proton?
1
What is the relative mass of a Neutron?
1
What is the relative mass of an Electron?
1/1830
What are the units for Specific Charge?
CKg-1
What is the equation for Specific Charge?
Q/m
What is a Nucleon?
A particle in the nucleus
What are Isotopes?
Versions of the same element, they have the same proton number but different number of neutrons
What is another name for the Mass Number?
Nucleon number
What is another name for the Proton Number?
Atomic number
What is the Strong Nuclear Force?
An attractive force between nucleons
What is the range of the Strong Nuclear Force?
~ 3 fm
What does Strong Nuclear force do in an atom?
Overcomes the repulsion between positive protons and holds the nucleus together
What does the strong nuclear force do at short ranges?
Becomes a repulsive force
At what range does strong nuclear force become repulsive?
~ 0.5 fm
Why does the strong nuclear force become repulsive at close range?
To stop the nucleus from collapsing in on itself
What is an alpha particle made up of? (2)
2 Protons, 2 Neutrons
What is an Alpha Particle the same as?
A helium nucleus
How fast is an Alpha compared to Gamma and beta?
Slowest
What is the charge of an Alpha Particle?
2+
What does the 2+ charge mean an Alpha is?
Strongly ionising
What is a Beta Particle?
1 electron
How fast is Beta compared to Alpha and Gamma?
Faster not fastest
What is the charge of a Beta Particle?
-1
What do we write for Beta’s atomic/proton number?
-1
What does the -1 charge mean a Beta Particle is?
Weakly ionising
How does a Beta Particle ionise?
By pushing/repelling electrons off atoms
How is a Beta Particle created?
A neutron turns into a proton and an electron (beta)
n -> ? + ?
p + β
Where does Beta Decay occur?
Proton rich nuclei
Where does Alpha Decay occur?
Large Nuclei
Which type of decay happens in neutron-rich nuclei?
β-, neutron emitter
Which type of decay happens in proton-rich nuclei?
β+, electron capture
How are Alpha Particles emitted from the nucleus?
The repelling of the other protons overcomes the strong nuclear force and pushes it out
In a Cloud Chamber what qualities do Alpha trails share, and why?
Length, because all alpha have the same kinetic energy
For Beta trails, do they share length, and why?
They don’t share length, they have varying kinetic energy, but the parent nucleus still loses the same energy
What explains the extra energy lost in Beta Decay?
The antineutrino
What qualities do corresponding Particles and Antiparticles share?
Rest mass and rest energy
What qualities do corresponding Particles and Antiparticles do not share?
Charge, baryon, lepton and strangeness numbers are opposite
What is an electron volt (eV)?
The work done by an electric field when accelerating an electron through a potential difference of 1 volt
Is an eV big or small?
Small
How many eVs are in 1MeV?
1 million
Rest energy is the energy equivalent to what?
Rest mass (when converted into energy)
What is the Electromagnetic Spectrum in order?
Radio, Microwave, Infrared, Visible, Ultraviolet, X-ray, Gamma ray
What is the longest wave length in the EM spectrum?
Radio
What is the shortest wavelength in the EM spectrum?
Gamma ray
What on the EM spectrum has the lowest frequency?
Radio waves
What on the EM spectrum has the highest frequency?
Gamma rays
Speed of light in a vacuum?
300 x 10^8 ms^-1