Electronic Structure of Atoms

What is electromagnetic radiation composed of?

Oscillating electric and magnetic fields that propagate through space.

What equation relates energy, frequency, and wavelength in electromagnetic radiation?

E = hf = hc/λ

What does the electromagnetic spectrum include?

A range of wavelengths/frequencies including gamma rays, X-rays, ultraviolet, visible light, infrared, microwaves, and radio waves.

How do you calculate wavelength from frequency?

λ = c/f

What does Heisenberg's Uncertainty Principle state?

It is impossible to simultaneously know both the exact position and momentum of a particle.

What is the Photoelectric Effect?

Demonstrates that light can eject electrons from a material, indicating light has particle-like properties (photons).

What is de Broglie's Hypothesis?

Particles exhibit wave-like characteristics; the wavelength associated with a particle is inversely proportional to its momentum.

What are the four quantum numbers?

Principal (n), Azimuthal (l), Magnetic (ml), and Spin (ms).

What principle states no two electrons can have the same set of quantum numbers?

Pauli Exclusion Principle.

What is the Aufbau Principle?

Electrons fill orbitals starting from the lowest energy level to higher levels.

What happens to atomic radii as you move across a period?

Atomic radii decrease due to increased effective nuclear charge.

What is effective nuclear charge (Z_eff)?

The net positive charge experienced by an electron in a multi-electron atom.

What trend occurs with ionization energy across a period?

Ionization energy increases across a period.

How does electron affinity change down a group?

Electron affinity generally decreases down a group.

What is the significance of periodic trends in chemical reactivity?

Reactivity is influenced by position in the periodic table, trends in ionization energy, electron affinity, and atomic radii.