Electronic Structure and Periodic Properties of Elements Practice Flashcards

Vocabulary terms and definitions from Chapter 3 relating to electromagnetic energy, the Bohr model, and the development of quantum theory.

Electromagnetic (EM) Radiation

A form of energy that travels through space, is emitted by moving charged particles, and exhibits wavelike behavior.

Wave

An oscillation or periodic movement that can transport energy from one point in space to another.

Wavelength ($\lambda$)

The distance between two consecutive peaks or troughs in a wave, often measured in $m$ or $nm$.

Frequency ($\nu$)

The number of waves or cycles per second that pass a given point in space, with units of $s^{-1}$ or hertz ($Hz$).

Speed ($c$)

The constant speed at which light moves, commonly rounded to the value $3.00 \times 10^8\,m/s$.

Stationary Waves

Waves constrained within some region of space, exhibiting quantization such that their wavelengths are limited to discrete multiples of certain lengths.

Quantization

The occurrence of discrete values from a general set of continuous values for a specific property.

Nodes

The points on a vibrating string between the end points that are not moving.

Black Body Radiation

The electromagnetic radiation of different wavelengths emitted by solids when they are heated.

Quanta

Discrete quantities or small bundles of radiant energy that can be emitted or absorbed, as suggested by Max Planck.

Planck’s constant ($h$)

A physical constant used to calculate energy via the formula $E = nh\nu$, with a value of $6.63 \times 10^{-34}\,J\cdot s$.

Photoelectric Effect

The emission of electrons from a metal surface when light of at least a certain minimum threshold frequency shines upon it.

Threshold frequency

The minimum frequency required for incident light to eject an electron from a metal surface.

Photons

Particles comprising a stream of light, used by Albert Einstein to explain the photoelectric effect.

Wave-particle duality

The concept that light behaves both as a wave and as a stream of particles termed photons.

Continuous Spectrum

A spectrum, such as white light passing through a prism, that contains all the wavelengths of visible light.

Line Spectra

A spectrum produced by excited atoms and molecules that emits only certain wavelengths, appearing as lines with gaps between them.

Rydberg constant ($R_{\infty}$)

A constant used in an empirical formula to predict hydrogen's emission lines, valued at $1.097 \times 10^7\,m^{-1}$.

Bohr Model

A model that assumes electrons move around the nucleus in circular orbits with discrete energy levels labeled by quantum numbers.

de Broglie wavelength

The wavelength associated with a submicroscopic particle, calculated by the formula $\lambda = \frac{h}{mv}$, where $m$ is mass and $v$ is velocity.

Heisenberg Uncertainty Principle

The principle stating it is fundamentally impossible to determine simultaneously and exactly both the momentum ($p$) and the position ($x$) of a particle.

Wavefunction ($\psi$)

A mathematical function from the Schrödinger wave equation that signifies the amplitude of the electron wave.

Hamiltonian Operator ($H$)

A set of mathematical instructions that extracts information from the wavefunction in the Schrödinger equation.

Probability Density ($\psi^2$)

The square of the wavefunction, which describes the likelihood of an electron being in a certain region of space.

Orbital

A region within an atom where an electron is found 90% of the time, characterized by maximum probability density.

Principal Quantum Number ($n$)

A positive integer ($1, 2, 3, 4, \dots$) that describes the size and energy level of the orbital; also called the shell.

Angular Momentum Quantum Number ($\ell$)

A quantum number that defines the three-dimensional shape of the orbital; also called the subshell.

Magnetic Quantum Number ($m_{\ell}$)

A quantum number that defines the spatial orientation of an orbital, ranging from $-\ell$ to $+\ell$.

Spin Quantum Number ($m_s$)

A quantum number describing the direction of the electron's spin, with values of $+\frac{1}{2}$ or $-\frac{1}{2}$.

Degeneracy

A condition where all orbitals with the same principal quantum number ($n$) have the same energy level, such as in the hydrogen atom.