Difference Between an Element and a Compound

Element

• An element is a pure substance made up of only one type of atom. All atoms in an element have the same number of protons in their nucleus, giving the element its unique atomic number

• Elements cannot be broken down into simpler substances by chemical means

• Examples of elements include iron (Fe), gold (Au), oxygen (O), and carbon (C)

• Elements are represented by symbols on the periodic table, such as H for hydrogen or Na for sodium

• There are currently about 118 known elements, most of which occur naturally

Compound

• A compound is a pure substance formed when two or more different elements are chemically bonded together in fixed proportions

• The atoms in a compound are held together by chemical bonds (ionic, covalent, or metallic), and the compound has properties different from the elements that compose it

• Compounds can be broken down into simpler substances (elements or simpler compounds) by chemical reactions

• Examples of compounds include water (H₂O), salt (NaCl), and glucose (C₆H₁₂O₆)

• Compounds are represented by chemical formulas, such as H₂O for water or NaCl for salt

Why Elements and Compounds Are Pure Substances

Both elements and compounds are considered pure substances because they have a uniform and definite composition throughout. An element contains only one type of atom, while a compound contains only one type of molecule (made from atoms of different elements in fixed ratios)

. This distinguishes them from mixtures, which contain two or more substances physically combined and can vary in composition.

Summary Table

Property| Element| Compound
---|---|---
Composition| One type of atom| Two or more different elements chemically combined
Can be separated by chemical means?| No| Yes
Representation| Symbol (e.g., O, Na, Fe)| Chemical formula (e.g., H₂O, NaCl)
Example| Oxygen (O₂), Iron (Fe), Gold (Au)| Water (H₂O), Salt (NaCl), Glucose (C₆H₁₂O₆)
Pure substance?| Yes| Yes

In summary:

• An element is a pure substance made of one kind of atom and cannot be broken down further by chemical means.
• A compound is a pure substance made of two or more different atoms chemically bonded in a fixed ratio and can be broken down into its elements by chemical reactions