Electromagnetic Waves, Quantum Physics, and Light Phenomena: Student Notes Review

LED

Which lamp uses semiconductor technology?

Total internal reflection

What phenomenon allows light to stay inside fiber optic cables?

Gamma rays

X-rays are similar to what type of radiation?

Because their free electrons reflect light.

Why are metals shiny?

Light behaves like a wave

What does Thomas Young's double-slit experiment prove?

White

If neon atoms did not have discrete energy levels, what color would neon lights appear?

Electromagnetic waves

What are electromagnetic waves made of?

The angle in equals the angle out.

What does the law of reflection state?

Particle theory of light

Did Einstein's photoelectric effect support the wave theory or particle theory of light?

Laser photons all move together in the same direction and are in sync, while bulb photons spread out randomly.(Coherent photons)

How do photons in a laser differ from those in incandescent bulbs?

Invisible

Most electromagnetic waves are...

Phosphorescence

A watch dial that glows for days in the dark is an example of...

Radio waves travel much faster—they move at the speed of light.

How fast do radio waves travel in air compared to sound?

Fluorescence glows only while light is on; phosphorescence keeps glowing after the light is off.

What is the difference between fluorescence and phosphorescence?

Microwaves

Which photons have lower energy: microwaves or X-rays?

Two straight bands

If electrons behaved only like particles in a double-slit experiment, what would appear on the screen?

Same time

If light and radio signals leave Alpha Centauri at the same time, which arrives first?

Alpha lowers it by 2, beta raises it by 1, gamma doesn’t change it.

How do alpha, beta, and gamma decay change atomic number?

Visible light

Glass is transparent to what type of light?

Energy equation(E=h×f)

What is the equation that relates photon energy to frequency?

Coherent light has one wavelength and phase, while sunlight has many wavelengths and phases.

How is coherent light different from sunlight?

Phosphors

What causes visible light in fluorescent lamps?

Hot surfaces.

A mirage appears over what type of surfaces?

Radioactive decay inside the Earth.

What is Earth's main internal heat source?

Lead

Natural uranium eventually decays into what element?

Yes, because it contains radioactive potassium-40.

Is the human body naturally radioactive? Why?

Because light travels through space, and Earth’s atmosphere is clear to visible light.

Why can we see stars at night?

Sound waves

Which type of wave cannot travel in a vacuum?

The highest frequency and highest energy.

Shortest wavelength waves have what frequency and energy?

Red light

Which color light passes through red glass?

Electrons.

For which object are quantum uncertainties significant?

it increases.

What happens to light speed when moving from water to air?

Engineers, surgeons, mechanics, and aviators — all of the above.

Who uses fiber optic cables?

Polarization

What phenomenon distinguishes transverse from longitudinal waves?