The Electromagnetic Spectrum and Light

Front

Electromagnetic Waves Noun

---

[ee-lek-troh-mag-net-ik wayvs]

Back

Electromagnetic Waves

---

Transverse waves of changing electric and magnetic fields that can travel through a vacuum or matter.

---

Example: This diagram shows the electromagnetic spectrum, arranging different types of electromagnetic waves like radio waves and X-rays by their changing wavelength.

Front

Electric Field Noun

---

[ee-lek-trik feeld]

Back

Electric Field

---

A region of space around a charged particle where a force is exerted on other charged particles.

---

Example: An electric field is the area around a charged particle. The field lines show the direction of the force, pointing away from positive charges and toward negative charges.

Front

Magnetic Field Noun

---

[mag-net-ik feeld]

Back

Magnetic Field

---

A region of space around a magnetic object or moving charge where a magnetic force is experienced.

---

Example: This diagram shows the invisible magnetic field around a bar magnet, with lines flowing from the North pole (N) to the South pole (S).

Front

Electromagnetic Radiation Noun

---

[ee-lek-troh-mag-net-ik ray-dee-ay-shun]

Back

Electromagnetic Radiation

---

Energy that is transferred through space by electromagnetic waves, which vary in wavelength and frequency.

---

Example: The Sun sends out energy in the form of electromagnetic radiation, which travels through space as waves to reach the Earth.

Front

Photoelectric Effect Noun

---

[foh-toh-ee-lek-trik ih-fekt]

Back

Photoelectric Effect

---

The emission of electrons from a metal's surface when it is struck by light of a certain frequency.

---

Example: When light (incident light) shines on a metal surface, it can knock out tiny particles called electrons (ejected photoelectrons) from the metal.

Front

Photons Noun

---

[foh-tons]

Back

Photons

---

Discrete packets or quanta of electromagnetic energy that behave like particles of light.

---

Example: When an electron in an atom drops to a lower energy level, it releases a packet of light energy called a photon.

Front

Intensity Noun

---

[in-ten-si-tee]

Back

Intensity

---

The power of light transferred per unit area, which decreases as light travels farther from its source.

---

Example: As light travels away from a source, it spreads out over a larger area. This diagram shows that the farther away you are, the less intense the light becomes.

Front

Electromagnetic Spectrum Noun

---

[ee-lek-troh-mag-net-ik spek-trum]

Back

Electromagnetic Spectrum

---

The complete range of all frequencies and wavelengths of electromagnetic radiation.

---

Example: This diagram shows the electromagnetic spectrum, arranging different types of waves like radio waves and X-rays by their changing wavelength and frequency.

Front

Amplitude Modulation Noun

---

[am-pli-tood mod-yoo-lay-shun]

Back

Amplitude Modulation

---

A method of transmitting information by varying the amplitude of a constant frequency carrier wave.

---

Example: This diagram shows how a low-frequency message signal, like sound, changes the amplitude (height) of a high-frequency carrier wave to create a modulated signal.

Front

Frequency Modulation Noun

---

[free-kwen-see mod-yoo-lay-shun]

Back

Frequency Modulation

---

A method of transmitting information by varying the frequency of a carrier wave.

---

Example: This diagram shows an audio signal changing the frequency of a carrier wave. Where the audio signal is high, the carrier wave's frequency increases.