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A molecule is the smallest particle of an element or compound capable of an independent life and exhibiting all of the substance's properties.
![shutterstock11697326831.jpg](https://resources.cdn.yaclass.in/2e8ab184-c6d8-4a7d-a20c-bba939e46117/shutterstock11697326831w500.jpg)
In general, a molecule is a set of two or more atoms that are chemically bound or held together by attractive forces.
Atoms from the same or different elements may combine to form a molecule.
Atoms from the same or different elements may combine to form a molecule.
Example:
- To understand it, consider a water molecule, the two elements, hydrogen and oxygen atoms combined, to form a water molecule.
- Calcium oxide \(CaO\) contains two elements, calcium and oxygen atoms combined to form a calcium oxide molecule.
- Oxygen \(O_2\) contains two elements of an oxygen atom.
- Chlorine \(Cl_2\) contains two elements of a chlorine atom.
![shutterstock_1865444311.jpg](https://resources.cdn.yaclass.in/a081727b-7a0f-4f84-be5f-299406d4167c/shutterstock1865444311w400.jpg)
Molecules of elements:
The atoms that make up an element's molecules are all of the same nature.
- Monoatomic Elements:
![shutterstock_463781411.jpg](https://resources.cdn.yaclass.in/70fb1fb9-814c-458a-9b28-e7183d449052/shutterstock463781411w300.jpg)
In their molecular form, certain elements are monatomic, meaning they are made up of just one atom (mono-atomic).
Helium \(He\) is an example of a monoatomic element.
- Diatomic Elements:
![shutterstock_1458144104.jpg](https://resources.cdn.yaclass.in/85aa9680-da07-49d1-9fb1-dddbe1c99395/shutterstock1458144104w336.jpg)
If the molecule constitutes two atoms, we can classify it as a diatomic molecule. In their molecular shape, other elements have two or more atoms.
Each molecule of hydrogen \(H_2\), oxygen \(O_2\), and chlorine \(Cl_2\), for example, has two atoms.
- Triatomic Elements:
![shutterstock_1465091945.jpg](https://resources.cdn.yaclass.in/8c005d27-1427-43d6-b6d0-debcf3352176/shutterstock1465091945w300.jpg)
If another atom is combined with , it forms ozone, which is a triatomic molecule.
Note:
- Monoatomic and diatomic molecules are more stable than triatomic molecules.
- Most non-metal elements are diatomic molecules.
Molecules of compounds:
Compound molecules contain atoms from two or more separate elements.
![shutterstock_209116279.jpg](https://resources.cdn.yaclass.in/b5a4cb94-9ae8-4333-91fa-d91b3bfc5d4a/shutterstock209116279w300.jpg)
Example:
Water \(H_2O\), for example, has three atoms: Two hydrogen (H) atoms and one oxygen (O).
![shutterstock_560960176.jpg](https://resources.cdn.yaclass.in/f139d3e5-fc68-4b4f-8e55-53b6e4fcea83/shutterstock560960176w300.jpg)
Methane \(CH_4\) with five atoms: One carbon (C) and four hydrogen (H) atoms.
Glucose \(C_6H_{12}O_6\) contains elements such as \(6\) carbon, \(12\) hydrogen and \(6\) oxygen, combined to form a glucose molecule.
![shutterstock_1818309464.jpg](https://resources.cdn.yaclass.in/69c18fc5-fdea-4071-b72b-2ce5c9e1798d/shutterstock1818309464w300.jpg)
Sodium chloride \(NaCl\) contains the one element of each sodium and chlorine combined to form a sodium chloride molecule.