Elements, Compounds and Mixtures
Everything you see around you is made from a combination of elements, compounds, and mixtures. Understanding the difference between them is a key part of Chemistry.
What is an element?
An element is a substance made of only one type of atom. All the atoms in an element have the same number of protons.
There are just over 100 elements, and they’re all listed in the periodic table. Examples include:
- Oxygen (O) – used for breathing
- Gold (Au) – used in jewellery
- Hydrogen (H) – the lightest element
Elements cannot be broken down into anything simpler by chemical means.
What is a compound?
A compound is a substance made when two or more elements are chemically bonded together.
The elements in a compound are present in fixed proportions, and they cannot be easily separated.
Examples of compounds:
Compound | Elements it contains | Formula |
Water | Hydrogen and Oxygen | H₂O |
Carbon dioxide | Carbon and Oxygen | CO₂ |
Sodium chloride | Sodium and Chlorine | NaCl |
💡 The properties of a compound are usually very different from the elements that make it.
What is a mixture?
A mixture contains two or more substances (elements or compounds) not chemically bonded together. They can be separated by physical methods like filtration, evaporation, or distillation.
Examples of mixtures:
- Air (a mixture of gases like oxygen, nitrogen, carbon dioxide)
- Seawater (a mixture of water, salts, and other substances)
- Crude oil (a mixture of different hydrocarbons)
In a mixture:
- Each substance keeps its own properties
- The composition can vary
Comparing elements, compounds, and mixtures
Type | Made of | Bonded? | Can be separated easily? | Example |
Element | One type of atom | No (just atoms) | No | Oxygen (O₂) |
Compound | Two or more elements | Yes (chemically) | No (needs a chemical reaction) | Water (H₂O) |
Mixture | Elements and/or compounds | No (physically mixed) | Yes (physical methods) | Air |
Questions
- What is an element made of?
- How is a compound different from a mixture?
- Can elements in a compound be separated easily?
- What is the difference in bonding between compounds and mixtures?
- Give one example of a mixture and explain why it is not a compound.
Summary
- Elements contain only one type of atom.
- Compounds are made of two or more elements chemically bonded in fixed ratios.
- Mixtures contain elements or compounds that are not chemically bonded.
- Mixtures can be separated physically.
- The properties of mixtures and compounds differ from the elements they contain.