Electronic Structure and Periodic Properties of Elements

These flashcards cover essential vocabulary related to electronic structure and periodic properties of elements, based on Chapter 6 of CHEMISTRY 121.

Electromagnetic Radiation (EM)

Energy that travels as oscillating electric and magnetic fields, moving through a vacuum at the speed of light.

Wavelength (λ)

The distance between two identical adjacent points on a wave, measured in units of length such as meters, centimeters, or nanometers.

Frequency (ν)

The number of waves passing a point in a second, measured in Hertz (Hz), which is the inverse of the period.

Amplitude

The intensity or height of the wave.

Inversely Proportional

A relationship where an increase in one quantity corresponds to a decrease in another, as seen with wavelength and frequency.

Planck's Constant (h)

A constant value of 6.626 x 10⁻³⁴ J·s, used in the equation Energy = E = hv to relate energy to frequency.

Photon

A particle of light representing a quantum of electromagnetic energy.

Photoelectric Effect

The emission of electrons from a metal when exposed to electromagnetic radiation of sufficient energy.

Threshold Energy

The minimum energy required to remove an electron from an atom, specific to each metal.

Emission Spectrum

A spectrum of wavelengths or frequencies of electromagnetic radiation emitted by high-energy (excited) atoms or molecules.

Absorption Spectrum

A spectrum of wavelengths or frequencies absorbed when electromagnetic radiation is passed through a sample of atoms or molecules.

Quantum Mechanics

The field of physics that describes the behavior of matter and energy at the atomic and subatomic level, taking into account both wave and particle properties.

Heisenberg Uncertainty Principle

A principle stating that it is impossible to simultaneously know both the momentum and position of an electron with precision.

Electron Configuration

The distribution of electrons in an atom's orbitals, described by the principal quantum number and other quantum numbers.

Electronegativity

A measure of an atom's tendency to attract electrons when chemically combined with another atom.

Ionic Radius

The size of an ion, which differs from the atomic radius of the neutral atom, where cations are smaller and anions are larger.

Valence Electrons

Electrons in the outermost shell of an atom that typically participate in chemical bonding.

Pauli Exclusion Principle

No two electrons in an atom can have identical sets of the four quantum numbers, hence an atomic orbital can hold a maximum of two electrons.

Hund's Rule

A rule stating that electrons will occupy degenerate orbitals singly before pairing up.

Periodic Law

The properties of the elements are periodic functions of their atomic numbers, leading to trends across the periodic table.