Subjects
Subscribe
Search Skwirk
Year 9 NSW
»
Science
»
Introducing chemistry
»
Atomic theory
Topic : Atomic theory
In this topic you will learn...
Chapter 1 :
Introduction to atoms
An atom is the smallest form of a chemical particle
Atomism is the philosophy of the existence of atoms
An atom contains three sub-atomic particles: protons; neutrons; electrons
Protons are positively charged particles
Electrons are negatively charged particles
Neutrons are particles with no charge
A nucleus is made up of protons and neutrons and is surrounded by electrons
Chapter 2 :
Introduction to elements
An element is a substance made up of one type of atom
An atomic number is the number of protons in an element
All atoms of the same element have the same number of protons
An isotope is a form of element with the same number of protons but a different number of neutrons
The mass number of an atom is the sum of its protons and neutrons
Chapter 3 :
The periodic table
Dmitri Mendeleev and Julius Meyer both developed the template for today`s periodic table
The name `periodic table` comes from its arrangement of elements into regular intervals
Metals comprise approximately 80% of the periodic table
Metalloids are elements that have both metallic and non-metallic properties
Noble gases are the most stable elements
The more reactive metals are found towards the left and the bottom of the table
The more reactive non-metals are found towards the right and the top of the table (excluding the noble gases)
All atoms have seven electron shells
Electron shells fill in stages, from innermost to outermost
Each electron shell has a maximum capacity of electrons
Topic Summary
Audio Summary
Play
|
Download
Text Summary
This topic includes
11 colour images
5 flash animations
1 final exam
ToolBox
Increase text size
Print this page
EMPTY?