Electron Cloud Model

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Slide 1

Ch. 10 - Atomic Structure

II. Electron Cloud Model

(p.272-274)

Orbital

Energy Levels

Bohr Model Diagrams

Slide 2

Orbital

Region where there is 90% probability of finding an electron.

Can’t pinpoint the location of an electron.

Density of dots represents degree of probability.

Slide 3

A. Orbital

Orbitals have different shapes.

Slide 4

Energy Levels

Electrons can only exist at certain energy levels.

Low energy levels are close to the nucleus.

Each energy level (n) can hold 2n2 electrons.

Slide 5

Bohr Model Diagrams

Simplified energy levels using Bohr’s idea of circular orbits.

e-

e-

Maximum e-

Level 1 2e-

Level 2 8e-

Level 3 18e-

Level 4 32e-

Lithium

Atomic #: 3

Mass: 7

# of p: 3

# of e: 3

# of n: 4

e-

Slide 6

C. Bohr Model Activity

Choose a number between 1 & 18.

Find your element by the atomic number you picked.

Draw a Bohr Model diagram for your element on your marker board.

Round off the mass listed on the table and subtract the atomic # to find the # of neutrons.

Abbreviate the # of ‘p’ and ‘n’ in the nucleus.

Have a partner check your drawing.

Repeat with a new element.