Chemistry Lesson 1: Light and Quantized Energy

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Wavelength (λ)

The shortest distance between equivalent points on a continuous wave.

Frequency (ν)

The number of waves that pass a given point per second (measured in Hertz).

Speed of light (c)

3.00 × 10^8 m/s

Wavelength and frequency

They are inversely related.

Formula for speed of light

c = λ × ν

Electromagnetic spectrum

Includes all forms of electromagnetic radiation, with energy higher at one end and lower at the other.

Electromagnetic radiation

A form of energy that exhibits wavelike behavior as it travels through space, modeled as a wave of changing electric and magnetic fields.

Examples of electromagnetic radiation

Visible light, microwaves, X-rays, and television and radio waves.

Photon

a massless particle; particle of electromagnetic radiation.

Quantum Concept

Matter can gain or lose energy only in small, specific amounts called quanta.

Quantum

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

Excited atom

An atom that has absorbed energy and its electrons jump up to a higher energy level.

Ground state atom

A condition in which an atom's electrons have their lowest possible energies.

Atomic emission spectrum

The set of frequencies of electromagnetic waves emitted by atoms of the element.

Max Planck

Showed a direct relationship between the energy of a quantum and the frequency of emitted radiation.

Planck's Constant (h)

6.626 × 10^-34 J·s

Energy Formula

E = h × ν, where E is the energy of a particle of light (photon).

Albert Einstein's proposal

Proposed that light has a dual nature, meaning that a beam of light has both wavelike and particle-like properties.

Photoelectric effect

Electrons (called photoelectrons) are emitted from a metal's surface when light (photons) at or above a certain frequency shines on the surface.

Which term refers to a form of energy that exhibits wavelike behavior as it travels through space?

Electromagnetic radiation

What happens to the frequency of an electromagnetic wave when the wavelength decreases?

It increases

What is amplitude?

Amplitude is the wave's height from the origin to a crest

Which of the following is true about amplitude?

Amplitude is the wave's height from the origin to a crest

What is a quantum?

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

What is the lowest allowable energy state of an atom called?

Ground state