Chemistry: General structure of atoms. Chemical elements of the living organisms, their atomic orbitals and electron configurations

Quantum

The amount of energy required to

move an electron to another energy

level.

Bohr’s model

Electrons are found in specific

circular paths (orbits) around the

nucleus.

Bohr’s model

The electrons have fixed energies

called energy levels. (like rungs on a

ladder)

The Quantum Mechanical model

It is based on the energy and possible

location of an electron.

The Quantum Mechanical model

Based on work done by Shrodinger

Dalton Model

Pictured atoms as tiny, indestructible particles with no internal structure.

Thompson Model

Pictured electrons as embedded in a sphere of positive electrical charge. Later leading to Plum pudding model.

Hantaro Nagaoka

Suggests that an atom has a central nucleus. Electrons move in orbits like rings around Saturn.

Rutherford Model

Finds that atoms have have small, dense, positively charged nucleus. Electrons move around the nucleus.

Bohr Model

Electron moves in a circular orbit at fixed distances from nucleus.

Louis de Broglie

Proposes that moving particles like electrons have some properties of waves.

Electron Cloud Model

Developed math equation to describe the motion of electrons in atoms. (Schrodinger)

James Chadwick

Confirmed the existence of neutrons, which have no charge.

Atomic Orbitals

The energy levels of electrons are labeled

by principal quantum numbers (n)

n = 1

Sublevel # = 1, Sublevel type = 1s (1 orbital)

n = 2

Sublevel # = 2, Sublevel type = 2s (1 orbital), 2p (3 orbital)

n = 3

Sublevel # = 3, Sublevel type = 3s (1 orbital), 3p (3 orbital), 3d (5 orbital)

n = 4

Sublevel # = 4, Sublevel type = 4s (1 orbital), 4p (3 orbital), 4d (5 orbital), 4f (7 orbital)

1s Orbital

Sphere around the nucleus. The one tells you that the electron

is in the orbital closest to the

nucleus

2s Orbital

Similar to 1s except the electron is most

likely in the region farther from the nucleus

p Orbitals

At the first energy level there is only the 1s

orbital, after the second energy level there

are 2p orbitals. Look like dumbbells. In the three directions

MAX NUMBER OF ELECTRONS

IN AN ENERGY LEVEL: 1

2

MAX NUMBER OF ELECTRONS

IN AN ENERGY LEVEL: 2

8

MAX NUMBER OF ELECTRONS

IN AN ENERGY LEVEL: 3

18

MAX NUMBER OF ELECTRONS

IN AN ENERGY LEVEL: 4

32

MAX NUMBER OF ELECTRONS

IN AN ENERGY LEVEL: 5

50

Electron

Configuration

A detailed way of showing the

order in which electrons fill in

around the nucleus

Aufbau principle

Electrons occupy energy levels with lowest

energy first.

Pauli exclusion principle

If 2 electrons occupy the same energy level

they must have opposite spins.

Hund’s rule

Electrons that occupy orbitals of the same

energy will have the maximum number of

electrons with the same spin.

p orbitals

orbitals look like

a dumbell with 3

orientations:

Four of the d orbitals

resemble two dumbells in a

clover shape.

1st Quantum #

Principle Quantum # (n)

Specifies the energy level

that the electron is on.

2nd Quantum #

Azimuthal Quantum number (1). Specifies the shape of the

sub level .

The 3rd (m) and 4th quantum

numbers (s)

Deals with the orbital within the sublevel

and the spin of the electron.

Energy Level S

Sub-level: Sphere, Type of sub: 2, # of

Orbitals: 1.

Energy Level P

Sub-level: Peanut, Type of sub: 6, # of

Orbitals: 3.

Energy Level D

Sub-level: 4-Lobed, Type of sub: 10, # of

Orbitals: 5.

Energy Level F

Sub-level: 6-8 Lobed, Type of sub: 14, # of

Orbitals: 7.

Periodic Table

"a substance that cannot be broken down into a simpler

substance by a chemical reaction". Boyle

Chanchortois

First person to arrange the chemical

elements

Newlands

Arranged in order of atomic weight. Undiscovered elements.

Dmitri Mendeleev

gets credit for the invention of the modern

periodic table in 1869

The Law of Octaves

stated that when elements are arranged by increasing atomic mass, every eighth element exhibits similar properties, much like how notes in a musical octave repeat.