electron config cehm tesm

Duality of light

Light exhibits properties of both waves and particles (photons).

Speed and wavelength equation of light

c = λν (Speed of light equals wavelength times frequency).

Energy of a photon equation

E = hν (Energy equals Planck's constant times frequency).

Electromagnetic spectrum order (increasing energy)

Radio waves, microwaves, infrared, visible, ultraviolet, X-rays, gamma rays.

Photoelectric effect

Emission of electrons from a metal surface when light of a sufficiently high frequency shines on it.

Planck's constant (h)

A fundamental physical constant relating energy to frequency (E = hν).

Heisenberg's Uncertainty Principle

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

Principal quantum number (n)

Indicates the main energy level or distance of the electron from the nucleus.

Angular momentum quantum number (l)

Indicates the shape of the orbital (s, p, d, f).

Magnetic quantum number (ml)

Indicates the spatial orientation of an orbital.

Spin quantum number (ms)

Indicates the direction of electron spin (+1/2 or -1/2).

Aufbau Principle

Electrons fill the lowest available energy orbitals first.

Hund's Rule

Orbitals of equal energy each get one electron with parallel spins before any gets a second electron.

Pauli Exclusion Principle

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

Chlorine (Cl) ion formation

Gains 1 valence electron to form a 1- anion (Cl⁻).

Rubidium (Rb) ion formation

Loses 1 valence electron to form a 1+ cation (Rb⁺).

Planck's constant numerical value

h = 6.626 × 10⁻³⁴ J·s

c (speed of light)

λν and 3.00 x 10^8 m/s

E (energy)

hv

1m

1 x 10^9 nm

1 kJ

1000 J

v (nu)

frequency

λ (lambda)

wavelength