Atoms, Elements and Compounds - Elements, Compounds and Mixtures

This section explores the fundamental building blocks of matter and the different ways they can be combined. We will define elements, compounds, and mixtures, and understand their key differences.

Elements

An element is a pure substance that consists of only one type of atom. It cannot be broken down into simpler substances by chemical means. Elements are represented by chemical symbols (e.g., H for hydrogen, O for oxygen, Fe for iron).

• Made up of only one type of atom.
• Cannot be broken down into simpler substances chemically.
• Represented by a chemical symbol.
• Found in the periodic table.

Compounds

A compound is a pure substance formed when two or more different elements are chemically bonded together in a fixed ratio. The properties of a compound are different from the properties of the elements that make it up.

• Made up of two or more different elements.
• Chemically bonded in a fixed ratio.
• Properties are different from the constituent elements.
• Can be broken down into simpler substances (elements) by chemical reactions.

Mixtures

A mixture is a combination of two or more substances that are physically combined but not chemically bonded. The components of a mixture retain their individual properties. Mixtures can be separated by physical means.

• A combination of two or more substances.
• Substances are physically combined, not chemically bonded.
• Components retain their individual properties.
• Can be separated by physical means (e.g., filtration, evaporation).

Key Differences: Elements, Compounds and Mixtures

The following table summarizes the key differences between elements, compounds, and mixtures:

Property	Element	Compound	Mixture
Composition	One type of atom	Two or more different elements chemically bonded	Two or more substances physically combined
Chemical Bonding	No chemical bonds between atoms of the same element.	Chemical bonds between different elements.	No chemical bonds between components.
Ratio of Components	N/A	Fixed ratio	Variable ratio
Separation	Cannot be separated by chemical means.	Can be broken down into elements by chemical reactions.	Can be separated by physical means.
Properties	Distinct properties.	Properties are different from the constituent elements.	Components retain their individual properties.

Understanding the differences between elements, compounds, and mixtures is crucial for further study in chemistry. This knowledge forms the basis for understanding chemical reactions and the properties of matter.