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First Hand Rule

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thumb - direction of charge flow fingers - curl in direction of magnetic field

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Second Hand Rule

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thumb - points towards magnetic north pole fingers - coil in direction of current

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Third Hand Rule

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thumb - direction of charge flow extended fingers - point towards SOUTH magnetic pole palm - direction of force

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Left Hand Rules

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Used for electron current

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Right Hand Rules

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Used for conventional current

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Dalton's Billiard Ball Model

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- all matter made of atoms - atoms are smallest particle of matter - atoms are indivisible - atoms of different elements have different properties; can combine in predictable whole number ratios

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Thomson atomic model experiment

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cathode ray tube experiment Proved the existence of sub-atomic particles in an atom. JJ Thompson took a cathode and an anode and placed them into a vacuum tube along with a pin-wheel and a a special screen that glowed green when hit. When Thompson passed electricity through the cathode and anode a ray was emitted on the screen. this ray had mass and was negatively charged.

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Thomson's Plum Pudding model

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free floating negative electrons inside a larger positively charged mass drawback: attraction between unlike charges should cause atom to collapse

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ruthfords atomic model experiment

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"gold foil" experiment This was Ernst Rutherford's experiment that led to the discovery of the nucleus as the small, dense, positively charged center of the atom and the development of the nuclear theory of the atom.

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Bohr atomic model

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Atoms described as electrons orbiting the nucleus at specific energy levels. Eph = ?Ee- = hf = hc/wavelength drawback: could only explain hydrogen emission spectrum, could not explain why moving e- didn't emit EMR

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Rutherford's Planetary Model

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Rutherford said that electrons move around a small nucleus just like planets orbit the sun drawback: attraction between unlike charges should cause atom to collapse

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relationship between frequency wavelength and energy

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The greater the energy, the larger the frequency and the shorter (smaller) the wavelength. Given the relationship between wavelength and frequency — the higher the frequency, the shorter the wavelength — it follows that short wavelengths are more energetic than long wavelengths.

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how does frequency, wavelength and energy form the electromagnetic (light) spectrum

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right side has bigger wavelengths but less enery the left side has smaller wavelengths and more energy and it has a higher frequency

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how does the atom absorbs specific light energies

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ground state-the lowest energy state of an atom or other particle. excited state-higher in energy than the ground state, moves up in rings

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de Broglie's hypothesis

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if waves can behave like particles, then particles can behave like waves

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electron diffraction experiment

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performed by Germer + Davisson and GP Thomson, provided evidence that particles could exhibit wavelike properties

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de Broglie atomic theory

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- electrons are circular standing waves around nucleus - electrons exist at locations of constructive interference and orbitals where the circumference is equal to whole number multiples of de Broglie wavelengths - electrons acting as waves don't emit EMR

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Schrodinger's Quantum Mechanical Model

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- electron cloud - region with high probability of finding an electron - limit to # of e- in each orbital

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Heisenberg's Uncertainty Principle

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it is impossible to know exactly both the momentum and the position of a particle at the same time

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Dirac

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predicted existence of anti-matter

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nucleons

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term that describes protons and neutrons

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isotopes

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atoms of the same element that have different numbers of neutrons

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strong nuclear force

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the powerful attractive force that binds protons and neutrons together in the nucleus idenpendent of charge

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nuclear mass defect

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the mass of every atom is measurably less than the total mass of its individual particles ?m = m (nucleons) - m (nucleus)

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mass-energy equivalence

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calculates energy lost in mass defect (converted to Ek of neutrons and nuclei or E of gamma photons)

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nuclear binding energy

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- the energy required to decompose an atomic nucleus into its component protons and neutrons - energy released when protons and neutrons come together to form atom

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radioactivity

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The process in which some substances spontaneously emit radiation (in form of EMR waves, charged particles, or uncharged particles)

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Becquerel (Bq)

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Measures the rate at which a sample of radioactive material decays (1Bq = 1 emission (or decay) per second)

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Geiger counter

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instrument that measures radiation output

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factors that determine radiation strength

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- type - amount - activity (amount of radiation produced over time)

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increase safety around radiation

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- less exposure time - more distance between people and source - more shielding

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biological effects of radiation

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- break chemical bonds - cell damage + mutation

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alpha particle properties

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- penetrating ability: paper - energy level: low - ionization ability: high - hazard level: low

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beta particle properties

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- penetrating ability: cardboard - energy level: low - ionization ability: moderate - hazard level: low

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gamma particle properties

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- penetrating ability: lead - energy level: high - ionization ability: low - hazard level: high

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unstable nuclides

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- have too few neutrons in relation to protons - tend to disintegrate - all atomic #s greater than 82 refer to these

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conservation laws that apply to all nuclear processes

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- conservation of charge, nucleons, momentum, and mass-energy

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top numbers in nuclear equations obey...

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law of conservation of nucleons

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bottom numbers in nuclear equations obey...

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law of conservation of charge

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alpha decay

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alpha particles emitted in this decay

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beta positive decay

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positrons emitted in this decay Note: massless and chargeless NEUTRINOs produced

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beta negative decay

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negative electrons emitted in this decay Note: massless and chargeless ANTI-NEUTRINO produced

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gamma decay

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emission of high E photon in this decay no transmutation occurs Note: gamma photon is massless and chargeless

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when radiation separated using electric or magnetic fields...

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alpha particle - less curvature than beta beta particle - greatest curvature gamma particle - no curvature

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factors that affect radioactivity

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- mass of sample (more sample, more ____ ) - half-life these are factors affecting ___

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half-life

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length of time required for half of the radioactive atoms in a sample to decay (refer to diagrams in booklets)

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half-life decay equation

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N = N0(1/2)^n N = amount of radioactive nuclei remaining N0 = original amount of sample n = number of half-lives

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number of half-lives equation

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n = t/t(1/2) t = time of decay = age t(1/2) = half-life

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decay series

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a sequence of successive radioactive decays that proceeds until a stable nuclide is reached

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radioactive dating

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measurement of the amount of radioactive material (usually carbon 14) that an object contains C-14 half-life = 5730 years - cannot be used for objects older than 60,000 years old U-238 half-life = 4.5 billion years

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all elements beyond this are artificial and unstable

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uranium

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artificial transmutation

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creating new elements (usually in particle accelerator)

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nuclear fission

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The process by which a large nucleus is split into smaller nuclei through a collision with a slow-moving neutron

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controlled vs uncontrolled fission reactions

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nuclear weapons vs nuclear power plants (demonstrates ___ )

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nuclear power plant moderator

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material (usually heavy water containing deuterium) that slows down high E neutrons emitted from fission reactions to sustain chain reaction

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nuclear power plant control rod

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between fuel rods, absorbs neutrons, prevents overheating

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advantages of nuclear power

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- extremely high energy density - easy to trigger

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disadvantages of nuclear power

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- radioactive waste - gamma shielding required - non-renewable

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nuclear fusion

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The process by which two or more small nuclei fuse to make a bigger nucleus powers the stars and hydrogen bombs

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nuclear fusion releases energy because...

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binding energy per nucleon greater than that of original nuclei

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as binding energy per nucleon increases...

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as the stability of the nucleus increases... (refer to diagrams in booklet)

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- factors that allow the sun to facilitate fusion reactions

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- high temp., high atom speed, overcome electrostatic repulsive forces, strong nuclear force binds atoms together

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- factors that allow fusion reactors on earth to work

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precise and strong magnetic fields overcome coulomb's force

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bubble chamber

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Ek of passing charged particles causes superheated liquid to boil, leaving tracks in this device

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cloud chambers

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moving charges cause gas condensation, leaving tracks in this device

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analyzing particle tracks

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- radii (lighter curves more than heavier) - charge - positive and negative curve in opposite directions (3rd hand rule) - neutral particles don't leave tracks - pair production (electron and positron produced by high E photon) refer to diagrams

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alpha particle track

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this particle track is: - broad - (+) charge

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proton particle track

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this particle track: - curves more than alpha, less than beta - (+) charge

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beta particle track

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this particle track: - curves the most - (+) or (-) charge

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as particles spiral in tracks...

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as particles in detection chambers lose energy..

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all equations from particle accelerators apply to...

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all equations from mass spectrometers apply to...

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energy of cosmic rays in the range of...

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10^2 - 10^14 MeV energy range for ___ rays

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cyclotron

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protons speed up across gap max speed at exit Eki = Ekf + Ep Fc = Fm

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standard model

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the current theoretical model that describes the fundamental particles and forces in nature

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leptons

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- don't interact with strong nuclear force -relatively small - mass, but no internal structure

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hadrons

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- don't interact with strong nuclear force -relatively large

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mesons

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- middle mass

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baryons

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- large mass

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fermions

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- half integer spin

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bosons

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- whole integer spin - move between quarks and leptons to produce fundamental forces

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quarks

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- discovered by Taylor - high E e- directed at protons, scattering patterns = unequal distribution of charge - 3 of each can make up a proton or neutron - fractional charges - cannot be isolated

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up quark

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+2/3 charge 1.5-4 MeV/c^2

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down quark

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-1/3 charge 4-8 MeV/c^2

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protons are made of...

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2 up, 1 down quarks

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neutrons are made of...

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1 up, 2 down quarks

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1. strong nuclear (within nucleus) force carrier

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gluon

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2. electromagnetic (infinite) force carrier

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photon

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3. weak nuclear (between quarks) force carrier

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W and Z bosons

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4. gravity (infinite) force carrier

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graviton

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strengths of the standard model

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- experiments support predictions - electron scattering verifies quark's existence - organizes subatomic particles - incorporates special relativity - predicted W and Z bosons

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weaknesses of the standard model

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- doesn't explain different size and mass of particles - doesn't account for gravity - doesn't work with general relativity - doesn't reveal necessity of 2nd and 3rd gen. particles - matter and anti-matter discrepancy

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