Science 9 - Electromagnetic Waves

Comprehensive vocabulary flashcards covering the properties, types, and relationships of electromagnetic waves based on the Grade 9 science curriculum.

Wave

A disturbance that transfers energy from one place to another.

Mechanical waves

Waves that require a medium or material to travel, such as sound waves.

Electromagnetic (EM) waves

Waves produced by changing electric and magnetic fields that do not need a medium and can travel through empty space.

Speed of EM waves in vacuum

Approximately $3 \times 10^8\,m/s$, which is the speed of light.

Wavelength ($\lambda$)

The distance between corresponding points of consecutive waves, measured in meters ($m$).

Frequency ($f$)

The number of complete waves passing a point per second, measured in hertz ($Hz$).

Amplitude

The maximum displacement from the rest position; in EM waves, it is related to the intensity or energy carried.

Electromagnetic Spectrum

The complete range of electromagnetic radiation arranged by wavelength, frequency, or energy.

Radio waves

EM waves with the longest wavelength, lowest frequency, and lowest energy; primarily used for broadcasting and communication.

Microwaves

EM waves used for communication, radar, microwave ovens, and satellite communication.

Infrared

EM waves used in heat-related applications, thermal imaging, and remote controls.

Visible light

The portion of the electromagnetic spectrum detected by human eyes; used for vision, lighting, and photography.

Ultraviolet

EM waves from the Sun used in sterilization; excessive exposure can be harmful to the skin and eyes.

X-rays

EM waves used for medical imaging because they can pass through soft tissues.

Gamma rays

The highest-energy EM waves with the highest frequency and shortest wavelength; used in medical treatments.

ROYGBIV

The acronym for the order of visible light colors from longest to shortest wavelength: Red, Orange, Yellow, Green, Blue, Indigo, Violet.

Frequency and Wavelength Relationship

These properties are inversely related, expressed by the formula $c = f\lambda$.

Frequency and Energy Relationship

These properties are directly related; higher frequency waves carry higher energy.