The Quantum Mechanical Atom

This set of flashcards covers key concepts from Chapter 7 of the chemistry lecture notes on the Quantum Mechanical Atom.

What are the two descriptions of light covered in Chapter 7?

Light is described as both a particle and a wave.

What is the relationship between energy, wavelength, and frequency of light?

They are related by the equation λ × ν = c (where λ is wavelength, ν is frequency, and c is the speed of light).

What model examines the line spectrum of hydrogen?

The Bohr model of hydrogen.

What shapes are used to describe atomic orbitals?

Shapes of s, p, and d orbitals.

Define quantum numbers in the context of electron configuration.

Quantum numbers are sets of numerical values that describe the unique quantum state of an electron in an atom, including its energy level, shape, orientation, and spin.

How does electromagnetic radiation travel?

It travels through space at the speed of light in a vacuum.

What does amplitude in wave properties represent?

Amplitude represents the maximum height of the wave and is associated with the intensity or brightness of the wave.

What occurs during the photoelectric effect?

When light of a certain frequency shines on a metal surface, electrons are ejected if the frequency exceeds a threshold.

Who proposed that energy is quantized and introduced the concept of quanta or photons?

Max Planck and Albert Einstein.

What is the formula for the energy of a photon?

E = hν, where E is the energy, h is Planck's constant, and ν is the frequency.

How can you describe the electronic structure of an atom?

Through studies of light absorption and emission, where electrons absorb energy to move to an 'excited state' or release energy to drop to a 'ground state'.

What is a line spectrum?

A spectrum with only a few discrete lines, unique to each element, formed by excited atoms releasing specific wavelengths.

What is the Rydberg equation used for?

To calculate the wavelengths of spectral lines in hydrogen's emission spectrum.

What does the Pauli Exclusion Principle state?

No two electrons in the same atom can have the same set of four quantum numbers.

What is the significance of the Heisenberg Uncertainty Principle?

It states that you cannot simultaneously know the exact position and exact momentum of a particle.

What are the effects of Zeff on ionization energy?

Ionization energy increases across a period due to increasing effective nuclear charge (Zeff).

Define effective nuclear charge (Zeff).

The net positive charge experienced by outer-shell electrons, accounting for shielding by inner electrons.

What is the general trend in atomic size as you move down a group in the periodic table?

Atomic size increases down a group due to the addition of electron shells.

What happens to the ionic size of cations compared to their parent atoms?

Cations are smaller than their parent atoms due to the loss of electrons and unchanged nuclear charge.

What is Hund's Rule regarding electron configuration?

Electrons will occupy degenerate orbitals singly before any orbital is doubly occupied.

What effect does electron spin have on magnetic properties?

Paired electrons (with opposite spins) produce diamagnetic properties; unpaired electrons produce paramagnetic properties.

How are electron configurations typically represented?

By listing subshells and their electron populations as superscripts or using orbital diagrams.

What determines the shape of atomic orbitals?

The secondary quantum number (ℓ) determines the shape of orbitals: s is spherical, p is dumbbell-shaped, and d has various complex shapes.

What distinguishes electron affinity from ionization energy?

Electron affinity measures the energy change when adding an electron, while ionization energy measures the energy required to remove an electron.

What happens to atomic radius when moving across a period?

Atomic radius decreases across a period due to increasing nuclear charge that pulls electrons closer.