Edufest 2013
Sec 3 Chemistry Timeline
Topic

Date

Kinetic Particle Theory

Jan

Experimental Techniques

Jan-Feb

Elements, Compounds and
Mixtures

Feb

Atomic Structure

Feb-Mar

Chemical Bonding

Mar-Apr

Chemical Equations

Apr

Acids, Bases and Salts

Apr-May

Chemical Calculations

Jun-Jul

The Atmosphere and
Environment

Jul-Aug

Revision

Sep-Oct
Atomic Structure
It Boils Down To Atoms!
Subatomic Particles

care
The Model of an Atom
•One negative
charge (1-)
•Negligible
mass
(1/1836)

•No electric
charge
•Relative
mass of 1

•One positive
charge (1+)
•Relative
mass of 1
Bohr Model of an Atom
Electron arrangement in an Atom
Rules for Drawing Electronic Structures
• An electron occupies the ___________before
pairing up with another.
• __________energy shells are occupied first.
• First shell, max = ___ electrons
• Second shell, max = ___ electrons
• Third shell, max = ___ electrons
• Fourth shell, max = ___ electrons
Electronic Structure of a Magnesium atom
Representing the Proton and Mass
Numbers

Neutral Atom : No of protons = No of electrons
Skills Practice 1
Drawing Electronic Structures

Could you spot some patterns?
What is the relationship between
these three atoms?

ISOTOPES! ATOMS OF THE SAME ELEMENT WITH THE SAME NUMBER OF PROTONS AND
ELECTRONS, BUT DIFFERENT NUMBER OF NEUTRONS.
Skills Practice 2
T/F
Skills Practice 3

Atomic structure student version