Electromagnetic Radiation and Atomic Models

Electromagnetic Radiation

Energy that travels in waves through space.

Wavelength (λ)

The distance between successive wave crests.

Frequency (ν)

The number of wave cycles per second (measured in Hertz, Hz).

Quantum

The minimum amount of energy that can be gained or lost by an atom.

Photon

A particle of light energy that carries a quantum of energy.

Atomic Emission Spectrum

The unique pattern of light emitted by an element when its electrons move between energy levels.

Speed of Light Equation

c = λν

Speed of Light (c)

3.00 × 10⁸ m/s (speed of light).

Planck's Equation (Energy of a Photon)

E = hν

Energy (E)

Energy measured in Joules.

Planck's Constant (h)

6.626 × 10⁻³⁴ J·s.

Electromagnetic Spectrum

A range of all types of electromagnetic radiation, ordered by energy.

Radio Waves

Lowest energy, longest wavelength, lowest frequency.

Microwaves

Low energy, long wavelength, low frequency.

Infrared

Medium energy, medium wavelength, medium frequency.

Visible Light

Higher energy, shorter wavelength, higher frequency.

Ultraviolet (UV)

High energy, short wavelength, high frequency.

X-rays

Very high energy, very short wavelength, very high frequency.

Gamma Rays

Highest energy, shortest wavelength, highest frequency.

Bohr's Model of the Atom

Proposed that electrons move in fixed orbits (energy levels) around the nucleus.

Energy Levels (n)

Electrons in higher orbits have more energy.

Quantum Mechanical Model

Electrons do NOT travel in fixed orbits but exist in regions called orbitals.

Heisenberg Uncertainty Principle

States that it is impossible to know both the position and velocity of an electron simultaneously.