Introduction to Chemical Bonding
Chemical bonds form when atoms combine to make compounds. At Year 7, students are introduced to the basic ideas of why atoms bond and the difference between elements, compounds, and mixtures.
What You Need to Know
Key Concept Diagram
Atoms bond with other atoms to achieve a more stable electron arrangement
A compound is formed when atoms of two or more elements are chemically joined in a fixed ratio, e.g. water (H2O)
A mixture contains two or more substances that are not chemically combined and can be separated by physical means
Chemical formulas show the types and numbers of atoms in a compound, e.g. CO2 = 1 carbon + 2 oxygen
Key Vocabulary
Chemical bond
The force of attraction holding two or more atoms together in a compound
Compound
A substance formed when atoms of two or more elements are chemically combined in a fixed ratio
Mixture
Two or more substances that are physically combined but not chemically joined
Chemical formula
A notation showing the types and numbers of atoms in a compound, e.g. H2O
Knowledge Check
Select the correct answer for each question. Click "Check Answer" to see if you are right.
Question 1
What is the chemical formula for water?
Question 2
Which of the following is a compound?
Question 3
How is a compound different from a mixture?
Key Concepts Summary
- ●Atoms bond with other atoms to achieve a more stable electron arrangement
- ●A compound is formed when atoms of two or more elements are chemically joined in a fixed ratio, e.g. water (H2O)
- ●A mixture contains two or more substances that are not chemically combined and can be separated by physical means
- ●Chemical formulas show the types and numbers of atoms in a compound, e.g. CO2 = 1 carbon + 2 oxygen