• Which part of an atom is positively charged, and which part is negatively charged?

• How does the charge of one electron compare with that of another electron?

• How do the masses of electrons compare with the masses of protons?

• What kind of charge does an object acquire when electrons are stripped from it?

• How is Coulomb's law similar to Newton's law of gravitation?

• How is Coulomb's law different to Newton's law of gravitation?

• How does the magnitude of electrical force between a pair of charged particles change when the particles are moved twice as far apart? Three times as far apart?

• What kind of force field surrounds an electric charge?

• What happens if an electric charge is placed in an electric field?

• In what way is the rule for the interaction between magnetic poles similar to the rule for the interaction between electric charges?

• In what way are magnetic poles very different from electric charges?

• What is the origin of all magnetic fields?

• What is a magnetic domain?

• Why is iron magnetic and wood not magnetic?

• In what ways can magnets lose their strength over time?

• Name two objects that create a magnetic field.

• What effect does the Earth's magnetic field have on the intensity of cosmic rays striking the Earth's surface?

• What are the three ways in which voltage can be induced in a loop of wire?

• How can a car moving along a paved road activate a traffic signal?

• What is the source of all waves?

• Distinguish between the period, amplitude, wavelength, and frequency of a wave.

• Does the medium in which a wave travels move with the wave? Why or why not?

• What is the relationship between frequency, wavelength, and wave speed?

• In what direction are the vibrations in a transverse wave, relative to the direction of wave travel?

• In what direction are the vibrations in a longitudinal wave, relative to the direction of wave travel?

• How does the speed of sound in water compare with the speed of sound in air?

• How does the speed of sound in steel compare with the speed of sound in air?

• Why doesn't sound travel in a vacuum?

• How are electromagnetic waves produced?

• List the frequencies of the electromagnetic spectrum in order from low to high frequencies.

• List the frequencies of the electromagnetic spectrum in order from short to long wavelengths.

• What is the principal difference between a radio wave and visible light?

• What is the fate of the energy in ultraviolet light incident on glass? Infrared light incident on glass? Visible light?

• What is the law of reflection?

• What is refraction?

• What is the angle between a light ray and its wave front?

• Which has the higher frequency: red light or blue light?

• Why is the sky blue?

• Why are sunsets red?

• Why are clouds white?