# Atomic nucleus

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• Created by: syaqub18
• Created on: 16-04-15 15:56
What conclusions can be made from the Rutherford experiment?
Nuclei is positive to repel positively charged alpha particles, Nuclei is small as few alpha particles are deflected at large angles and most pass through, most of mass and charge is in nucleus as alpha particles pass through
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What is Rutherford’s scattering experiment?
An experiment which demonstrates the existence of an atomic nucleus
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How is the Rutherford experiment set up?
An alpha source emits a stream of alpha particles at a thin gold foil. A fluorescent screen is set up which produces a flash of light when hit by an alpha particle
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What is the angle of an alpha particle which “bounces back”?
180 degrees
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At the point an alpha particle bounces back, what is its initial kinetic energy equal to?
To its electric potential energy
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What is the equation for the distance of closest approach?
Initial Ek = (charge on nucleus x charge of alpha particle) / (4pi epsilon 0 x r) where r is the distance
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How can you find the charge of a particle?
Use proton number Z and multiply by e
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What is the distance of closest approach to the nucleus used for?
An estimate for the nuclear radius
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What gives a more accurate estimate for the nuclear radius?
Electron diffraction
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How do you change from electron volts to joules?
Multiply by the charge of an electron
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Why can electron beams be diffracted?
Because they can experience wave-particle duality
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Why can electron diffraction give an accurate estimate of the radius?
Because electrons are leptons and don’t interact by the strong nuclear force (which protons and neutrons interact by)
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What is the radius of an atom?
0.1nm
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What is the diameter of the smallest nucleus?
1fm
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what is the typical radius of a nucleus?
x10^-15
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what are nucleons?
particles that make up the nucleus (protons and neutrons)
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What happens as the nucleon number increases?
The radius of the nucleus increases
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What is the value of r0?
1.4 fm
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Which density is the highest, atomic or nuclear?
nuclear
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What does the density of a nucleus suggest?
Most of an atoms mass is in the nucleus, nucleus is small compared to the atom, an atom contains a lot of empty space
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## Other cards in this set

### Card 2

#### Front

What is Rutherford’s scattering experiment?

#### Back

An experiment which demonstrates the existence of an atomic nucleus

### Card 3

#### Front

How is the Rutherford experiment set up?

#### Back ### Card 4

#### Front

What is the angle of an alpha particle which “bounces back”?

#### Back ### Card 5

#### Front

At the point an alpha particle bounces back, what is its initial kinetic energy equal to?

#### Back 