1.3- Electron configurations

What is Light?

Light is a form of electromagnetic radiation that exhibits both wave-like and pariticle-like properties. It consists of particles calles photons and can be transmitted as electromagnetic waves..

Photons

Light particles with a specific amount of energy but have no mass

Electromagnetic waves

Waves that transfer energy through electric and magnetic fields

How can light be described as a wave?

By its wavelength frequency and speed

Wavelength(λ)

The distance between identical points on two consecutive waves

Frequency (f)

The number of wave cycles passing a point each second. Measured in Hertz (Hz)

Speed of light in a vacuum?

3.00 × 10 8

What equation connects speed, frequency and wavelength?

speed of light equals frequency times wavelength

Relationship between wavelength and energy

inversley proportional

Relationship between wavelength and frequency

Inversely proportional

Relationship between frequency and energy

Directly proportional

what are the visible wavelength for the human eye

400-700nm

Continous spectrum and how is it produced

A spectrum containing all visible wavelengths. Produced by passing white light through a prism

Which visible light has the longest wavelength but the lowest frequency and energy?

Red light

Which visible light has the shortes wavelength and the highest frequency and energy?

Violet light

What did Niels Bohr discover about electrons?

Electrons occupy discrete, fixed energy levels

What is a ground state

The electron’s lowest energy level

What is an excited state?

An electron’s higher energy level reached after absorbing energy

What happens when the electron’s extra energy is no longer suppied?

The electron falls to a lower energy level and releases a photon in the proccess

What determines the energy of the emitted photon?

The energy difference between the initial and final levels

What hapens when the energy gap is larger?

The photon has a greater energy, higher frequency, and shorter wavelength

What happens when the energy gap is smaller?

The photon has less energy, lower frequency, and longer wavelength.

What is a line emission spectrum and what does it prove?

Sharp bright lines against a dark background are produced when electrons transition between energy levels. Proves quantised energy levels

What happens to spacing at higher energy levels?

The levels become closer together

What do transitions to levels 1,2, and 3 produce?

Level one produces UV, level 2 produces visible, level 3 produces infrared

What is an orbital?

Region with a high probability of finding an electron

What is the maximum electrons per orbitals?

two with opposite spins

What are the four sub-levels and its orbital capacities?

s:1,p:3,d:5,f:7

What are degenerate orbitals?

Orbitals within the same sublevel that have the same energy level and can hold electrons with identical energy.

What happens to orbital distance as energy increases?

Its distance from the nucleus increases

What is an electron configuration?

Distribution of electrons among an atom’s orbitals

Aufbau principle

The Aufbau principle is the rule that electrons occupy the lowest energy orbitals available first before filling higher energy orbitals.

Pauli Exclusion Principle

Each orbital can hold a maximum of two electrons with opposite spins

Hund’s rule

Hund's rule states that electrons will occupy degenerate orbitals singly and with the same spin before pairing up in orbitals.

Why are Chromium and Copper exceptions to the predicted electron configurations?

Because the 4s and 3d sublevels are very close in energy, making and electron from the 4s moves to the 3d with a small energy cost, resulting in more stable filled and fully filled sublevels.

Condensed electron configuration

The symbol of the nearest group 18 element (noble gas) in square brackets followed by the remaining terms of the atom

Electron Configuration of Ions

Anions: Electrons are added to the next available orbital

Cations: Electrons are removed from the outermost orbital