Unit 2: Electrons Part A - Light and Photoelectric Effect

Vocabulary practice flashcards covering quantum theory, electron energy transitions, electromagnetic wave equations, and photoelectric solar applications.

Photoelectric Effect

The phenomenon in which electrons are emitted from a metal surface when light of a high or certain frequency shines on it.

Photon Emission

The release of a photon that occurs when an atomic electron transitions from a high energy state down to a low energy state.

Hydrogen Line Spectrum

The emission spectrum of excited hydrogen that Bohr used to discover the specific discrete energies of each energy level in the hydrogen atom.

Wave Equation

The mathematical equation formulated by Erwin Schrödinger that contributed to the Quantum Mechanical model of the atom and the concept of electron clouds.

Distance from Nucleus vs. Energy

A direct relationship in an atom where an electron positioned further from the nucleus is more excited and possesses more energy.

Electron Duality

The concept proved by Louis de Broglie establishing that an electron behaves simultaneously as both a wave and a particle.

Heisenberg Uncertainty Principle

The principle formulated by Werner Heisenberg stating that it is impossible to determine both the speed and location of electrons at the same time.

Speed of Light ($c$)

A constant defined as $3 \times 10^8\,\text{m/s}$, related to wavelength and frequency by the equation $c = \lambda \nu$.

Planck's Constant ($h$)

A physical constant with the value of $6.626 \times 10^{-34}\,\text{J}\cdot\text{s}$, used in the energy equation $E = h\nu$.

Wavelength and Frequency Proportionality

An indirect relationship where an increase in wavelength corresponds to a decrease in frequency.

Wavelength and Energy Proportionality

An indirect relationship where radiation with a longer wavelength carries less energy.

Frequency and Energy Proportionality

A direct relationship where radiation with a higher frequency carries greater energy.

Atomic Emission Spectrum

A unique physical property of an element consisting of distinct wavelengths of light emitted when excited electrons fall to lower energy levels, used to identify unknown elements.

Excitation and Relaxation (Bohr Model)

The process where electrons become excited upon gaining energy, and subsequently release emitted photons of light as they drop back down to lower energy levels like $n=1$.

Solar Power (Photoelectric Application)

The technology utilizing metallic materials such as silicon; when sunlight strikes the silicon, electrons are knocked loose and converted into electricity.

Violet Light (in Solar Energy)

The visible light color that works best for solar power because it has the lowest wavelength, highest energy, and emits the most electrons to generate the most electricity.