CHM 4

Flashcards covering key vocabulary and concepts from the lecture on Light and Electronic Structure, including solar energy, electromagnetic radiation, atomic models, quantum mechanics, and electron configurations.

Solar Cell

A device that can convert sunlight into electricity.

Edmond Becquerel

A French scientist who discovered in 1839 that shining light on certain materials produced an electric current.

Bell Labs

Produced the first solar cell in 1954.

Solar Energy

A clean, renewable power source that converts sunlight into electricity and is seen as a potential replacement for fossil fuels.

Tesla Battery System

A rechargeable home battery system, based on Tesla automotive technology, capable of powering a small home by storing daytime solar panel energy for nighttime use, reducing power bills.

Electromagnetic Radiation

A form of energy that travels in waves and is produced when charged particles move or vibrate relative to each other.

Photon

A small increment or packet of electromagnetic energy.

Electromagnetic Spectrum

The broad continuum of all forms of electromagnetic energy, ranging from very low-energy waves (TV and radio waves) to very high-energy waves (X-rays and gamma rays).

Visible Spectrum

The narrow range of electromagnetic energy that our eyes can detect and perceive as light, containing the colors of the rainbow (red, orange, yellow, green, blue, violet).

Wavelength (λ)

The distance from a point on one wave to the same point on the next wave.

Frequency (ν)

The number of waves that pass through a point in one second.

Hertz (Hz)

A unit of frequency equal to one wave cycle per second (1/s or s⁻¹).

Speed of Light (c)

A constant value of 3.00 × 10⁸ m/s in a vacuum, represented by the relationship c = λν.

Planck’s Constant (h)

A constant value of 6.63 × 10⁻³⁴ J ⋅ s, used to relate the energy of a photon (E) to its frequency (ν) by E = hν.

Flame Test

A laboratory experiment in which a wire dipped in a solution containing metal ions produces a characteristic color when heated in a flame.

Line Spectrum

A pattern of light energies, or spectral lines, formed when gas-phase elements release energy, unique to each element.

Continuous Spectrum

A spectrum showing all of the visible colors, produced when white light passes through a prism.

Photoelectric Effect

The phenomenon where high-energy light can knock electrons off of some atoms.

Bohr Model

An early model of atomic structure proposing that electrons orbit the nucleus in specific, allowed energy levels and transition between them by absorbing or releasing light.

Ground State

The state of an atom where its electrons are in the lowest possible energy levels.

Excited State

The state of an atom where its electrons have jumped to higher energy levels after absorbing energy.

Fluorescence

The phenomenon where a substance absorbs invisible UV energy and then releases it in lower-energy steps as visible light.

Quantum Model

The modern description of electronic behavior that treats electrons as both particles and waves, replacing the Bohr model for larger elements.

Quantum Mechanics

A field of study that deals with the unique and surprising behavior of subatomic particles, describing electrons as both particles and waves.

Uncertainty Principle (Heisenberg’s)

The idea that it is impossible to know the exact velocity and location of a particle simultaneously, particularly significant for tiny, fast-moving particles like electrons.

Principal Quantum Number (n)

A whole number (1, 2, 3, etc.) that identifies the energy level an electron occupies, with lower numbers indicating lower energy levels closer to the nucleus.

Sublevel

A set of electron orbitals that occurs within an electron energy level, designated by the letters s, p, d, and f.

Orbital

The region around an atom where an electron is most likely to be found, with each orbital capable of holding up to two electrons.

s Sublevel

A sublevel that contains one spherical orbital and can hold a maximum of two electrons, present in every energy level.

p Sublevel

A sublevel that contains three orbitals, each shaped like an infinity symbol, and can hold a maximum of six electrons, present in energy levels 2 and higher.

d Sublevel

A sublevel that contains five orbitals with complex geometries and can hold a maximum of 10 electrons, present in energy levels 3 and higher.

f Sublevel

A sublevel that contains seven orbitals with complex geometries and can hold a maximum of 14 electrons, present in energy levels 4 and higher.

Electron Spin

A tiny magnetic field of an electron, which, when two electrons occupy the same orbital, causes their spins to orient in opposite directions.

Hund’s Rule

The principle that if empty orbitals of the same energy are available, electrons will singly occupy those orbitals rather than pairing together in one orbital.

Electron Configuration

A notation that shows the number of electrons in each occupied energy level and sublevel within an atom.

Valence Level (Valence Shell)

The highest-occupied electron energy level in an atom, where chemical changes typically occur.

Octet Rule

The principle that an atom is stabilized by having its highest-occupied (valence) energy level completely filled, typically with eight electrons in the s and p sublevels.

Noble Gas

An element located in the far-right column of the periodic table, characterized by a completely filled valence level, making it stable and unreactive.

Noble Gas Shorthand (Notation)

A simplified way to write electron configurations by representing the filled inner electron shells with the symbol of the preceding noble gas in square brackets.

Inner Electrons

The electrons within the filled core noble gas configuration of an atom, which do not typically participate in chemical bonding.

Outer Electrons

Electrons beyond the largest filled noble gas configuration, including valence electrons and those in partially filled d and f sublevels, involved in chemical bonds.

Isoelectronic

A term describing atoms or ions that have identical electron configurations.

Alkali Metals

Elements in the first column (Group 1A) of the periodic table, all having an s¹ valence electron configuration.

Alkaline Earth Metals

Elements in the second column (Group 2A) of the periodic table, all having an s² valence electron configuration.

Halogens

Elements in Group 7A of the periodic table, all having an s²p⁵ valence electron configuration, and tending to form ions with a −1 charge.

p-n Junction

A design used in most solar cells where two slightly different semiconductors (p-type and n-type) are placed next to each other to convert sunlight into electrical current.

n-type Semiconductor

A semiconductor material containing tiny amounts of an element with an s²p³ valence configuration (like arsenic), which provides easily removed high-energy electrons (negative charges).

p-type Semiconductor

A semiconductor material containing tiny amounts of an element with an s²p¹ valence configuration (like gallium), which has empty orbitals capable of accepting additional electrons.