nuclear physics

What was Thompson theory

Plum pudding model

What was Rutherford discovery

discovery of a nucleus

Alpha particle characteristics

Pass through nucleus, very few are deflected

Particle doesn’t touch the nucleus

Characteristics of a nucleus

Diameter is much less of an atom

Contains most mass/more dense

When a alpha particle is closest to a nucleus, what does that show

Electrostatic repulsion will increase and therefore lowest speed in path

What are the charges if a proton and electron

1.602 ×10^-+19

How to calculate the density of nuclear matter

Mass no. X proton rest mass/4/3 pi r ³

What is the volume proportional to

No.nucleons

How to calculate radius of nuclei

Initial radius x no. Of nucleons^1/3

What is the no. At the top of an element

Mass no

Total protons and nucleons

No. At the bottom of an element is

Atomic no

No. Of electrons,protons

What is a radioisotope

Isotopes that emit ionising radiation

Unstable so are likely to decay and absorb into a lower energy state

Alpha decay

Beta neg decay

Beta pls decay

Electron capture

He 4,2 so minus that

e 0,-1 so plus 1 plus antineutrons

e 0,+1 so minus 1 plus neutrino

e0,-1 but u actually minus 1 plus a neutrino

How to find the average count rate after…

Count rate recorded by source-background count rate

That total half it until the no. Of half lives

That answer plus background count rate

Ionisation, penetration and speed of alpha, beta and gamma

Alpha=high,paper or few cm or air, slow

Beta=moderate ionisation,few m of aluminium, fast

Gamma=low,cm of lead,speed of light

what is decay constant and how to calculate it

Probability of a single nucleus decaying per unit time

Ln2/half life

What is activity and its equation

Rate of decay of nuclei in a radioactive sample

Change in no. Of nuclei present over change in time

Or -decay constant x no. Of nuclei present

How to find out how old something is

Calculate decay constant

N=initial N to the power of e to the power of -decay constant x time

Mass of 1 mole of an element

Mass/no. Of atoms

1 u equals

Mass of 1 atom of an element/no. Of nucleons

What is binding energy

Minimum energy required to separate a nucleus into its separate nucleons or energy released on formation of a nucleus from its separate neutrons and protons

What is the binding energy equal to

Difference between the rest energy of a nucleus and rest energy of its constituent neutrons and protons

if E=mc², E can also equal to

Change in mass x 1u

If carbon has a mass of 12, how many atomic mass units (u) are there

12 u

Calculate binding energy per nucleon (BEPN)

Binding energy/no. Of nucleons

Nuclear fusion equation

Element +1 in mass no.(no. At the top) n

What is a nuclear reactor common material for moderating, controlling and shielding

Graphites, boron and concrete