Basics of Electromagnetic Radiation and Atomic Models

These flashcards cover key vocabulary and concepts related to electromagnetic radiation, atomic models, quantum principles, and periodic trends.

Electromagnetic radiation

Energy that travels through space as waves, such as light, X-rays, and microwaves.

Wavelength (λ)

The distance between two wave peaks; longer wavelength means lower energy.

Frequency (ν)

The number of waves that pass a point per second; higher frequency means higher energy.

Amplitude

The height of the wave; relates to brightness or intensity, not energy.

Speed of light (c)

The constant speed at which light travels in a vacuum, approximately 3.00 × 10⁸ m/s.

Planck’s Constant (h)

A fundamental constant (6.626 × 10⁻³⁴ J·s) used to calculate the energy of a photon.

Line spectrum

Specific colors of light emitted by electrons dropping to lower energy levels.

Quantum model

The modern atomic model where electrons exist in orbitals instead of fixed paths.

Ground state

The lowest energy state of an atom.

Excited state

When electrons absorb energy and jump to higher energy levels.

Orbital

A region where an electron is likely to be found, including s, p, d, and f orbitals.

Sublevel

Divisions within energy levels, such as 2s and 2p.

Energy level

Main levels where electrons exist, labeled n = 1, 2, 3, etc.

Quantum numbers

A set of numbers that describe the position and spin of electrons within an atom.

Hund’s Rule

Electrons fill orbitals singly before pairing in equal-energy orbitals.

Aufbau Principle

Electrons occupy the lowest energy orbital first.

Pauli Exclusion Principle

States that no two electrons can have the same set of four quantum numbers.

Valence electrons

Electrons in the outermost energy level, which are involved in bonding.

Lewis electron dot structure

A representation that shows valence electrons as dots around element symbols.

Ionization energy

The energy needed to remove an electron from an atom.

Electron affinity

The energy change when an atom gains an electron.

Atomic radius

The distance from the nucleus to the outermost electrons; decreases across a period and increases down a group.

Ionic radius

The radius of an ion; cations are smaller and anions are larger compared to the neutral atom.

Electronegativity

An atom's ability to attract electrons in a bond, with fluorine being the highest.

Nuclear charge

The total positive charge of the nucleus, equal to the number of protons.

Shielding

The phenomenon where inner electrons block the attraction between the nucleus and outer electrons.