AP Physics 2 course outline

9.1.A.1 · Atoms in a gas collide with and exert forces on other atoms in the gas and with the container in which the gas is contained.

9.1.B.1 · The temperature of a system is characterized by the average kinetic energy of the atoms within that system.

9.2.A.1 · The classical model of an ideal gas assumes that the instantaneous velocities of atoms are random, the volumes of the atoms are negligible compared to the total volume occupied by the gas, the atoms collide elastically, and the only appreciable forces on the atoms are those that occur during collisions.

9.2.A.2 · An ideal gas is one in which the relationships between pressure, volume, the number of moles or number of atoms, and temperature of a gas can be modeled using the equation = = PV nRT Nk T B.

9.2.A.3 · Graphs modeling the pressure, temperature, and volume of gases can be used to describe or determine properties of that gas.

9.2.A.4 · A temperature at which an ideal gas has zero pressure can be extrapolated from a graph of pressure as a function of temperature.

9.3.A.1 · Two systems are in thermal contact if the systems may transfer energy by thermal processes.

9.3.A.2 · The thermal processes by which energy may be transferred between systems at different temperatures are conduction, convection, and radiation.

9.3.A.3 · Energy is transferred through thermal processes spontaneously from a higher-temperature system to a lower-temperature system.

9.3.A.4 · Thermal equilibrium results when no net energy is transferred by thermal processes between two systems in thermal contact with each other.

9.4.A.1 · The internal energy of a system is the sum of the kinetic energy of the objects that make up the system and the potential energy of the configuration of those objects.

9.4.A.2 · Changes to a system’s internal energy can result in changes to the internal structure and internal behavior of that system without changing the motion of the system’s center of mass.

9.4.B.1 · The first law of thermodynamics is a restatement of conservation of energy that accounts for energy transferred into or out of a system by work, heating, or cooling.

9.4.B.2 · Pressure-volume graphs (also known as PV diagrams) are representations used to represent thermodynamic processes.

9.4.B.3 · Special cases of thermal processes depend on the relationship between the configuration of the system, the nature of the work done on the system, and the system’s surroundings. These include constant volume (isovolumetric), constant temperature (isothermal), and constant pressure (isobaric), as well as processes where no energy is transferred to or from the system through thermal processes (adiabatic).

9.5.A.1 · The amount of energy required to change the temperature of a material is related to the material’s specific heat. Relevant equation:

9.5.A.2 · The specific heat of a material is an intrinsic property of that material that depends on the arrangement and interactions of the atoms that make up the material.

9.5.B.1 · The rate at which energy is transferred by conduction through a given material is related to the thermal conductivity, the physical dimensions of the material, and the temperature difference across the material. Relevant equation:

9.5.B.2 · The thermal conductivity of a material is an intrinsic property of that material that depends on the arrangement and interactions of the atoms that make up the material.

9.6.A.1 · The second law of thermodynamics states that the total entropy of an isolated system can never decrease and is constant only when all processes the system undergoes are reversible.

9.6.A.2 · Entropy can be qualitatively described as the tendency of energy to spread or the unavailability of some of the system’s energy to do work.

9.6.A.3 · The change in a system’s entropy is determined by the system’s interactions with its surroundings.

10.1.A.1 · Charge is a fundamental property of all matter.

10.1.A.2 · Coulomb’s law describes the electrostatic force between two charged objects as directly proportional to the magnitude of each of the charges and inversely proportional to the square of the distance between the objects. Relevant equation:

10.1.A.3 · The direction of the electrostatic force depends on the signs of the charges of the interacting objects and is parallel to the line of separation between the objects.

10.1.A.4 · Electric forces are responsible for some of the macroscopic properties of objects in everyday experiences. However, the large number of particle interactions that occur make it more convenient to treat everyday forces in terms of nonfundamental forces called contact forces, such as normal force, friction, and tension.

10.1.B.1 · Electrostatic forces can be attractive or repulsive, while gravitational forces are always attractive.

10.1.B.2 · For any two objects that have mass and electric charge, the magnitude of the gravitational force is usually much smaller than the magnitude of the electrostatic force.

10.1.B.3 · Gravitational forces dominate at larger scales even though they are weaker than electrostatic forces, because systems at large scales tend to be electrically neutral.

10.1.C.1 · Electric permittivity is a measurement of the degree to which a material or medium is polarized in the presence of an electric field.

10.1.C.2 · Electric polarization can be modeled as the induced rearrangement of electrons by an external electric field, resulting in a separation of positive and negative charges within a material or medium.

10.1.C.3 · Free space has a constant value of electric permittivity, 0, that appears in physical relationships.

10.1.C.4 · The permittivity of matter has a value different from that of free space that arises from the matter’s composition and arrangement.

10.2.A.1 · The net charge or charge distribution of a system can change in response to the presence of, or changes in, the net charge or charge distribution of other systems.

10.2.A.2 · Any change to a system’s net charge is due to a transfer of charge between the system and its surroundings.

10.2.A.3 · Grounding involves electrically connecting a charged system to a much larger and approximately neutral system (e.g., Earth).

10.3.A.1 · Electric fields may originate from charged objects.

10.3.A.2 · The electric field at a given point is the ratio of the electric force exerted on a test charge at that point to the charge of the test charge. Relev ant equation:  E = E F q

10.3.A.3 · The electric field is a vector quantity and can be represented in space using vector field maps.

10.3.B.1 · While in electrostatic equilibrium, the excess charge of a solid conductor is distributed on the surface of the conductor, and the electric field within the conductor is zero.

10.3.B.2 · While in electrostatic equilibrium, the excess charge of an insulator is distributed throughout the interior of the insulator as well as at the surface, and the electric field within the insulator may have a nonzero value.

10.4.A.1 · The electric potential energy of a system of two point charges equals the amount of work required for an external force to bring the point charges to their current positions from infinitely far away.

10.4.A.2 · The general form for the electric potential energy of two charged objects is given by the equation

10.4.A.3 · The total electric potential energy of a system can be determined by finding the sum of the electric potential energies of the individual interactions between each pair of charged objects in the system.

10.5.A.1 · Electric potential describes the electric potential energy per unit charge at a point in space.

10.5.A.2 · The electric potential due to multiple point charges can be determined by the principle of scalar superposition of the electric potential due to each of the point charges. Relevant equation:

10.5.A.3 · The electric potential difference between two points is the change in electric potential energy per unit charge when a test charge is moved between the two points. Relevant equation:

10.5.A.4 · When conductors are in electrical contact, electrons will be redistributed such that the surfaces of the conductors are at the same electric potential.

10.5.B.1 · The average electric field between two points in space is equal to the electric potential difference between the two points divided by the distance between the two points. Relevant equation:

10.5.B.2 · Electric field vector maps and equipotential lines are tools to describe the field produced by a charge or configuration of charges and can be used to predict the motion of charged objects in the field.

10.6.A.1 · A parallel-plate capacitor consists of two separated parallel conducting surfaces that can hold equal amounts of charge with opposite signs.

10.6.A.2 · Capacitance relates the magnitude of the charge stored on each plate to the electric potential difference created by the separation of those charges. Relevant equation:

10.6.A.3 · The electric field between two charged parallel plates with uniformly distributed electric charge, such as in a parallel-plate capacitor, is constant in both magnitude and direction, except near the edges of the plates.

10.6.A.4 · The electric potential energy stored in a capacitor is equal to the work done by an external force to separate that amount of charge on the capacitor.

10.6.A.5 · The electric potential energy stored in a capacitor is described by the equation

10.6.A.6 · Adding a dielectric between two plates of a capacitor changes the capacitance of the capacitor and induces an electric field in the dielectric in the opposite direction to the field between the plates.

10.7.A.1 · When a charged object moves between two locations with different electric potentials, the resulting change in the electric potential energy of the object-field system is given by the following equation. Relevant equation:

10.7.A.2 · The movement of a charged object between two points with different electric potentials results in a change in kinetic energy of the object consistent with the conservation of energy.

11.1.A.1 · Current is the rate at which charge passes through a cross-sectional area of a wire. Relevant equation:

11.1.A.2 · Although current is not a vector quantity, it does have a direction. The direction of current is associated with what the motion of positive charge would be but not with any coordinate system in space.

11.2.A.1 · A circuit is composed of electrical loops, which may include circuit elements such as wires, batteries, resistors, lightbulbs, capacitors, switches, ammeters, and voltmeters.

11.2.A.2 · A closed electrical loop is a closed path through which charges may flow.

11.2.A.3 · A single circuit element may be part of multiple electrical loops.

11.2.A.4 · Circuit schematics are representations used to describe and analyze electric circuits.

11.3.A.1 · Resistance is a measure of the degree to which an object opposes the movement of electric charge.

11.3.A.2 · The resistance of a resistor with uniform geometry is proportional to its resistivity and length and is inversely proportional to its cross-sectional area. Relevant equation:

11.3.B.1 · Ohm’s law relates current, resistance, and potential difference across a conductive element of a circuit. Relevant equation:

11.4.A.1 · The rate at which energy is transferred, converted, or dissipated by a circuit element depends on the current in the element and the electric potential difference across it. Relevant equation: Derived equations:

11.4.A.2 · The brightness of a bulb increases with power, so power can be used to qualitatively predict the brightness of bulbs in a circuit.

11.5.A.1 · Circuit elements may be connected in series and/or in parallel.

11.5.A.2 · A collection of resistors in a circuit may be analyzed as though it were a single resistor with an equivalent resistance Req.

11.5.B.1 · Ideal batteries have negligible internal resistance. Ideal wires have negligible resistance.

11.5.B.2 · The internal resistance of a nonideal battery may be treated as the resistance of a resistor in series with an ideal battery and the remainder of the circuit.

11.5.B.3 · When there is current in a nonideal battery with internal resistance r, the potential difference across the terminals of the battery is reduced relative to the potential difference when there is no current in the battery. Derived equation: r

11.5.C.1 · Ammeters are used to measure current at a specific point in a circuit.

11.5.C.2 · Voltmeters are used to measure electric potential difference between two points in a circuit.

11.5.C.3 · Nonideal ammeters and voltmeters will change the properties of the circuit being measured.

11.6.A.1 · Energy changes in simple electrical circuits may be represented in terms of charges moving through electric potential differences within circuit elements. Relevant equation:

11.6.A.2 · Kirchhoff’s loop rule is a consequence of the conservation of energy.

11.6.A.3 · Kirchhoff’s loop rule states that the sum of potential differences across all circuit elements in a single closed loop must equal zero. Relevant equation:

11.6.A.4 · The values of electric potential at points in a circuit can be represented by a graph of electric potential as a function of position within a loop.

11.7.A.1 · Kirchhoff’s junction rule is a consequence of the conservation of electric charge.

11.7.A.2 · Kirchhoff’s junction rule states that the total amount of charge entering a junction per unit time must equal the total amount of charge exiting that junction per unit time. Relevant equation:

11.8.A.1 · A collection of capacitors in a circuit may be analyzed as though it were a single capacitor with an equivalent capacitance Ceq.

11.8.A.2 · As a result of conservation of charge, each of the capacitors in series must have the same magnitude of charge on each plate.

11.8.B.1 · The time constant is a significant feature of an RC circuit.

11.8.B.2 · The potential difference across a capacitor and the current in the branch of the circuit containing the capacitor each change over time as the capacitor charges and discharges, but both will reach a steady state after a long time interval.

12.1.A.1 · A magnetic field is a vector field that can be used to determine the magnetic force exerted on moving electric charges, electric currents, or magnetic materials.

12.1.A.2 · A magnetic field is a vector quantity and can be represented using vector field maps.

12.1.B.1 · Magnetic dipoles result from the circular or rotational motion of electric charges. In magnetic materials, this can be the motion of electrons.

12.1.B.2 · A magnetic dipole, such as a magnetic compass, placed in a magnetic field will tend to align with the magnetic field.

12.1.B.3 · A material’s composition influences its magnetic behavior in the presence of an external magnetic field.

12.1.B4 · Earth’s magnetic field may be approximated as a magnetic dipole.

12.1.C.1 · Magnetic permeability is a measurement of the amount of magnetization in a material in response to an external magnetic field.

12.1.C.2 · Free space has a constant value of magnetic permeability, known as the vacuum permeability µ0, that appears in equations representing physical relationships.

12.1.C.3 · The permeability of matter has values different from that of free space and arises from the matter’s composition and arrangement. It is not a constant for a material and varies based on many factors, including temperature, orientation, and strength of the external field.

12.2.A.1 · A single moving charged object produces a magnetic field.

12.2.B.1 · Magnetic forces describe interactions between moving charged objects.

12.2.B.2 · A magnetic field may exert a force on a charged object moving in that field.

12.2.B.3 · In a region containing both a magnetic field and an electric field, a moving charged object will experience independent forces from each field.

12.2.B.4 · The Hall effect describes the potential difference created in a conductor by an external magnetic field that has a component perpendicular to the direction of charges moving in the conductor.

12.3.A.1 · A current-carrying wire produces a magnetic field.

12.3.B.1 · A magnetic field may exert a force on a current- carrying wire.

12.4.A.1 · Magnetic flux is a description of the amount of the component of a magnetic field that is perpendicular to a cross-sectional area.

12.4.A.2 · Magnetic flux through a surface is proportional to the magnitude of the component of the magnetic field perpendicular to the surface and to the cross-sectional area of the surface. Relevant equation:

12.4.A.3 · Faraday’s law describes the relationship between changing magnetic flux and the resulting induced emf in a system. Relevant equation:

12.4.A.4 · Lenz’s law is used to determine the direction of an induced emf resulting from a changing magnetic flux. Relevant equation:

12.4.A.5 · A common example of electromagnetic induction is a conducting rod on conducting rails in a region with a uniform magnetic field. Derived equation:

13.1.A.1 · A light ray is a straight line that is perpendicular to the wavefront of a light wave and points in the direction of travel of the wave.

13.1.A.2 · Ray diagrams depict the path of light before and after an interaction with matter.

13.1.B.1 · Light that is incident on a surface can be reflected.

13.1.B.2 · The law of reflection states that the angle between the incident ray and the normal (the line perpendicular to the surface) is equal to the angle between the reflected ray and the normal. Relevant equation:

13.1.B.3 · Diffuse reflection is the reflection of light from a rough surface and results in light reflected in many different directions, because the line normal to the surface varies over the area over which the light is incident.

13.1.B.4 · Specular reflection is the reflection of light from a smooth surface and results in light uniformly reflected from the surface, because the line normal to the surface has an approximately constant direction over the area the light strikes.

13.2.A.1 · Incident light rays parallel to the principal axis of a concave (converging) mirror will be reflected toward a common location, called the focal point.

13.2.A.2 · Incident light rays parallel to the principal axis of a convex (diverging) mirror will be reflected such that they appear to have originated from a common location behind the mirror, called the focal point.

13.2.A.3 · The focal point of a plane mirror is an infinite distance from the mirror.

13.2.A.4 · The focal point of a spherical mirror may be approximated as a point located on the principal axis of the mirror halfway between the surface of the mirror and the center of the mirror’s radius of curvature.

13.2.A.5 · A real image is formed by a mirror when light rays emanating from a common point are reflected and then intersect at a common point.

13.2.A.6 · A virtual image is formed by a mirror when reflected light rays diverge such that they appear to have originated from a common point.

13.2.A.7 · The location of an image depends on the focal length of the mirror and the distance between the object and the surface of the mirror. Relevant equation: 1 1 1 + = s s f i o

13.2.A.8 · The magnification of an image formed by a mirror is the ratio of the size of the image produced to the size of the object itself and depends on the locations of the object and image relative to the mirror. Relevant equation: s i i = = M h h s o o

13.2.A.9 · Ray diagrams can be used to determine the location, type, size, and orientation of images formed by mirrors.

13.3.A.1 · Refraction is the change in direction of a light ray as the ray passes from one medium into another.

13.3.A.2 · Refraction is a result of the speed of light changing when light enters a new medium.

13.3.A.3 · The index of refraction of a given medium is inversely proportional to the speed of light in the medium. Relevant equation: c = n v

13.3.A.4 · Snell’s law relates the angles of incidence and refraction of a light ray passing from one medium into another to the indices of refraction of the two media. Relevant equation:

13.3.A.5 · Total internal reflection may occur when light passes from one medium into another medium with a lower index of refraction.

13.4.A.1 · Incident light rays parallel to the principal axis of a thin convex (converging) lens will be refracted and converge toward a common location on the transmitted side of the lens, called the focal point.

13.4.A.2 · Incident light rays parallel to the principal axis of a thin concave (diverging) lens will be refracted and diverge as if they originated from a focal point on the incident side of the lens.

13.4.A.3 · A real image is formed by a lens when light rays originating from a common point are refracted such that they intersect at another common point.

13.4.A.4 · A virtual image is formed by a lens when refracted light rays diverge such that they appear to have originated from a common point.

13.4.A.5 · For a thin lens, the location of an image depends on the focal length of the lens and the distance between the object and the midline of the lens, as given by the thin-lens equation: 1 1 1 + = . s s f i o

13.4.A.6 · For a thin lens, the magnification of an image is the ratio of the size of the image produced to the size of the object itself and depends on the locations of the object and image relative to the lens. Relevant equation: s i i = = M h h s o o

13.4.A.7 · Ray diagrams can be used to determine the location, type, size, and orientation of images formed by lenses.

14.1.A.1 · Waves transfer energy between two locations without transferring matter between those locations.

14.1.A.2 · Mechanical waves or wave pulses require a medium in which to propagate. Electromagnetic waves or wave pulses do not require a medium in which to propagate.

14.1.A.3 · The speed at which a wave or wave pulse propagates through a medium depends on the type of wave and the properties of the medium.

14.1.A.4 · In a transverse wave, the direction of the disturbance is perpendicular to the direction of propagation of the wave.

14.1.A.5 · In a longitudinal wave, the direction of the disturbance is parallel to the direction of propagation of the wave.

14.1.A.6 · Amplitude is the maximum displacement of a wave from its equilibrium position.

14.2.A.1 · Periodic waves have regular repetitions that can be described using period and frequency.

14.2.A.2 · A sinusoidal wave can be described by equations for the displacement from equilibrium at a specific location as a function of time. A wave can also be described by an equation for the displacement from equilibrium at a specific time as a function of position. Example equations:

14.2.A.3 · For a periodic wave, the wavelength is proportional to the wave’s speed and inversely proportional to the wave’s frequency. Relevant equation:

14.3.A.1 · A wave that travels from one medium to another can be transmitted or reflected, depending on the properties of the boundary separating the two media.

14.3.A.2 · Transverse waves that are reflected from a surface, refracted through a medium, or pass through specific openings may be polarized.

14.3.A.3 · Polarization of a wave may result in a reduction of the wave’s intensity.

14.4.A.1 · Electromagnetic waves consist of oscillating electric and magnetic fields that are mutually perpendicular.

14.4.A.2 · Electromagnetic waves do not need a medium through which to propagate.

14.4.A.3 · Categories of electromagnetic waves are characterized by their wavelengths.

14.5.A.1 · The Doppler effect describes the relationship between the rest frequency of a wave source, the observed frequency of the source, and the relative velocity of the source and the observer.

14.5.A.2 · A greater relative velocity results in a greater measured difference between the observed and rest frequencies.

14.6.A.1 · Wave interference is the interaction of two or more wave pulses or waves.

14.6.A.2 · When two or more wave pulses or waves interact with each other, they travel through each other and overlap rather than bouncing off each other.

14.6.A.3 · When two or more wave pulses or waves overlap, the resulting displacement can be determined by adding the individual displacements. This is called superposition.

14.6.A.4 · Wave interference may be constructive or destructive.

14.6.A.5 · Visual representations of wave pulses or waves are useful in determining the result of two interacting wave pulses or waves.

14.6.A.6 · Beats arise from the addition of two waves of slightly different frequency.

14.6.B.1 · Standing waves can result from interference between two waves that are confined to a region and traveling in opposite directions.

14.6.B.2 · A standing wave with the longest possible wavelength is called the fundamental or first harmonic. The second-longest wavelength is typically called the second harmonic, the third- longest wavelength is called the third harmonic, and so on. However, for a standing wave with a node at one end and an antinode at the other end, only odd harmonics can be established.

14.6.B.3 · Visual representations of standing waves are useful in determining the relationships between length of the region, wavelength, frequency, wave speed, and harmonic.

14.7.A.1 · Diffraction is the spreading of a wave around the edges of an obstacle or through an opening.

14.7.A.2 · Diffraction is most pronounced when the size of the opening is comparable to the wavelength of the wave.

14.7.A.3 · Diffraction of multiple wavefronts through a single opening leads to observable interference patterns.

14.7.A.4 · Diffraction is commonly demonstrated by monochromatic light of wavelength incident on a narrow opening of width a that is a distance L from a screen.

14.7.A.5 · The diffraction pattern produced by a wave passing through an opening depends on the shape of the opening.

14.7.A.6 · Visual representations of single-slit diffraction patterns are useful in determining the physical properties of the slit and the interacting waves.

14.8.A.1 · The pattern resulting from monochromatic light of wavelength incident on two slits a distance d apart is caused by a combination of wave diffraction and wave interference.

14.8.A.2 · Interference patterns produced by light interacting with a double slit indicate that light has wave properties. The source of this discovery was Young’s double-slit experiment.

14.8.A.3 · Visual representations of double-slit diffraction patterns are useful in determining the physical properties of the slits and the interacting waves.

14.8.A.4 · A diffraction grating is a collection of evenly spaced parallel slits or openings that produce an interference pattern that is the combination of numerous diffraction patterns superimposed on each other.

14.8.A.5 · When white light is incident on a diffraction grating, the center maximum is white and the higher-order maxima disperse white light into a rainbow of colors, with the longest-wavelength light (red) appearing farthest from the central maximum.

14.9.A.1 · When light travels from one medium to another, some of the light is transmitted, some is reflected, and some is absorbed.

14.9.A.2 · The phase change of a reflected ray depends on the relative indices of refraction of the materials with which the ray interacts.

14.9.A.3 · The phase of a wave does not change when it is refracted as it passes from one medium into another.

14.9.A.4 · Thin-film interference occurs when light interacts with a medium whose thickness is comparable to the light’s wavelength.

14.9.A.5 · Practical examples of thin-film interference include the color variations seen in soap bubbles and oil films, as well as antireflection coatings.

15.1.A.1 · Quantum theory was developed to explain observations of matter and energy that could not be explained using classical mechanics. These phenomena include, but are not limited to, atomic spectra, blackbody radiation, and the photoelectric effect.

15.1.A.2 · Light can be modeled both as a wave and as discrete particles, called photons.

15.1.A.3 · The speed of a photon depends on the medium through which the photon travels.

15.1.A.4 · Particles can demonstrate wave properties, as shown by variations of Young’s double-slit experiment.

15.1.A.5 · Values of energy and momentum have discrete, or quantized, values for bound systems described by quantum theory.

15.2.A.1 · Atoms have internal structure.

15.2.A.2 · Each atomic element has a unique number of protons.

15.2.A.3 · The Bohr model of the atom is based on classical physics and was the historical representation of the atom that led to the description of the hydrogen atom in terms of discrete energy states.

15.3.A.1 · Energy transfer occurs when photons are absorbed or emitted by an atom, which is modeled as a system consisting of a nucleus and an electron.

15.3.A.2 · Energy can only be absorbed or emitted by an atom if the amount of energy being absorbed or emitted corresponds to the energy difference between two atomic energy states.

15.3.A.3 · Transitions between two energy states of an atom correspond to the absorption or emission of a photon of a single frequency and, therefore, a single wavelength.

15.3.A.4 · Atoms of each element have a unique set of allowed energy levels and thereby a unique set of absorption and emission frequencies. The unique set of frequencies determines the element’s spectrum.

15.3.A.5 · Binding energy is the energy required to remove an electron from an atom, causing the atom to become ionized. An atom in the lowest energy level (ground state) will require the greatest amount of energy to remove the electron from the atom.

15.4.A.1 · Matter will spontaneously convert some of its internal thermal energy into electromagnetic energy.

15.4.A.2 · A blackbody is an idealized model of matter that absorbs all radiation that falls on the body. If the body is in equilibrium at a constant temperature, then it must in turn emit energy.

15.4.A.3 · A blackbody will emit a continuous spectrum that only depends on the body’s temperature. The radiation emitted by a blackbody is often modeled by plotting intensity per unit wavelength as a function of wavelength.

15.5.A.1 · The photoelectric effect is the emission of electrons when electromagnetic radiation is incident upon a photoactive material.

15.5.A.2 · The emission of electrons via the photoelectric effect requires a minimum frequency of incident light, called the threshold frequency.

15.5.A.3 · The maximum kinetic energy of an emitted electron is related to the frequency of the incident light and the work function of the material, .

15.6.A.1 · In Compton scattering, a photon interacts with a free electron. The Compton effect is when a photon that emerges from the interaction has a lower energy and longer wavelength than the incoming photon. The magnitude of the change is related to the direction of the photon after the collision.

15.6.A.2 · Compton scattering provides evidence that light is a collection of discrete, quantized energy packets called photons.

15.6.A.3 · The change in wavelength experienced by a photon after colliding with an electron is related to how much the photon’s direction changes. Relevant equation:

15.7.A.1 · The strong force is exerted at nuclear scales and dominates the interactions of nucleons (protons or neutrons).

15.7.A.2 · Possible nuclear reactions are constrained by the law of conservation of nucleon number.

15.7.A.3 · The behavior of the constituent particles of a nuclear reaction is constrained by laws of conservation of energy, energy-mass equivalence, and conservation of momentum.

15.7.A.4 · For all nuclear reactions, mass and energy may be exchanged due to mass-energy equivalence. Relevant equation: 2 = E mc

15.7.A.5 · Energy may be released in nuclear processes in the form of kinetic energy of the products or as photons.

15.7.A.6 · Nuclear fusion is the process by which two or more smaller nuclei combine to form a larger nucleus, as well as subatomic particles.

15.7.A.7 · Nuclear fission is the process by which the nucleus of an atom splits into two or more smaller nuclei, as well as subatomic particles.

15.7.A.8 · Nuclear fission may occur spontaneously or may require an energy input, depending on the binding energy of the nucleus.

15.7.B.1 · Radioactive decay is the spontaneous transformation of a nucleus into one or more different nuclei, or to a lower energy level of the same nucleus.

15.7.B.2 · A material’s decay constant may be used to predict the number of nuclei remaining in a sample after a period of time, or the age of a material if the initial amount of material is known. Relevant equation: Derived equation:

15.7.B.3 · Different unstable elements and isotopes may have vastly different half-lives, ranging from fractions of a second to billions of years.

15.8.A.1 · Some processes by which nuclei decay emit subatomic particles with unique properties.

15.8.A.2 · Nuclei can undergo radioactive decay via alpha dec ay, beta-minus decay , beta-plus decay ) , and gamma decay ( ).

15.8.A.3 · The type of decay exhibited by a given nucleus is determined by the isotope of the element.