Organic chemistry is the branch of chemistry that studies carbon-containing compounds. In the first part of the topic, students learn that carbon is unique because it can form four covalent bonds, allowing it to create a wide variety of compounds, including long chains and rings.

At Grade 9 IGCSE level, the focus is mainly on hydrocarbons, which are compounds made only of carbon and hydrogen. The simplest group of hydrocarbons is called alkanes. Alkanes are saturated compounds, meaning they have single bonds only between carbon atoms. Their general formula is CₙH₂ₙ₊₂, and examples include methane, ethane, and propane.

Students also learn how to represent organic molecules using displayed, structural, and molecular formulas. Another important idea is that the properties of hydrocarbons depend on their structure and bonding. These basic concepts form the foundation for understanding more complex organic reactions and compounds in later topics

<!--a=1-->