Electromagnetic spectrum and radiation

Question 1

What does the electromagnetic spectrum represent?

Answer 1

It represents the range of all types of electromagnetic radiation, from long wavelength, low-energy radio waves to short wavelength, high-energy gamma rays

Question 2

What are the common properties of all electromagnetic waves?

Answer 2

All electromagnetic waves transfer energy as radiation, can travel through a vacuum, and move at the speed of light (3 × 10⁸ m/s) in a vacuum.

Question 3

What is ionising radiation?

Answer 3

Ionising radiation is radiation with enough energy to remove an electron from an atom or molecule, creating ions.

Question 4

What is intensity in the context of electromagnetic waves?

Answer 4

Intensity is the total energy per second flowing past a unit area, measured in watts per square meter (W/m²).

Question 5

Inverse square law

Answer 5

The intensity of electromagnetic radiation is inversely proportional to the square of the distance from its source.

Question 6

What is the main difference between transverse and longitudinal waves?

Answer 6

Transverse waves have particle displacement perpendicular to the wave direction (e.g., light), while longitudinal waves have displacement parallel to the wave direction (e.g., sound).

Question 7

Dual wave theory

Answer 7

Electromagnetic radiation behaves as both a wave and a particle, with photons acting as discrete packets of energy

Question 8

Planck’s constant

Answer 8

Planck’s constant (6.626 × 10⁻³⁴ J·s) is the energy of a photon as proportional to its frequency, highlighting the quantum nature of energy.