Ch.15 Modern and Nuclear Physics

Hadrons

Particles that are affected by strong nuclear force, and contain quarks.

Protons and Neutrons.

Leptons

Are one of the classes of "fundamental particles" and are affected by weak nuclear force... Cannot be broken down. Electrons, Positrons, Neutrinos, Anti-neutrinos.

Proton quark composition

up up down

Neutron quark composition

up down down

Up, Top, and Charm quark charge

+2/3e

Down, Bottom, and Strange quark charge

-1/3e

The strange quark is strange because-

it lives longer than we would expect.

1. Charge is -1/3e with strangeness -1.

2. Antistrange is 1/3e Charge with strangeness 1

3. Other quarks have strangeness of 0

beta negative decay

Radioactive decay

decay of neutron into a proton

emission of an e- and an antineutrino.

A down quark decays to an up quark

Beta positive decay

Proton decays into a neutron and a beta positive particle and a neutrino.

An up quark decays to a down quark

Ionization radiation through an electric field.

1. B- Particle attracted to positive plate.

2. B+ Particle attracted to negative plate.

3. Alpha +2 Particle attracted to negative plate, but a longer arc than B+

4. Gamma particle no attraction... straight through

Rutherford Gold Foil Experiment

1. Most particles go straight through with no deflection... means

most of the atom is empty space.

2. With small deflections (less than 90 degrees)… means it is

near a positive particle

3. Very few particles have a deflection of greater than 90

degrees... means there is a very small, dense, positively

charged center called the nucleus.

Alpha particle radiation.

Parent nucleus emits a Helium nucleus and a smaller daughter particle.

+2e Charge

Slowest

Highest Ionization

Penetrates up to a few cm of air or paper

Reduces nucleon number by 4

Reduces Proton number by 2

gamma radiation

EM radiation emitted during radioactive decay and having an extremely short wavelength and high energy

Antineutrino

Neutrino

Types of Radiation

Baryon

A hadron consisting of three quarks.

Ex... uuu, uud, udd,...

Meson

A hadron consisting of a quark and an antiquark.

Anti-Quarks

1 electronvolt (1 eV)

The energy transferred when an electron travels through a potential difference of 1 volt.

Isotopes

Atoms of the same element that have different numbers of neutrons.

Weak nuclear force

Responsible for beta decay.

Strong nuclear force

the attractive force that binds protons and neutrons together in the nucleus.

unified atomic mass unit (u)

a unit of mass that is exactly 1/12 the mass of a carbon-12 atom.