What is an ions definition and examples?
Ions examples their classification and electrical neutrality of matter is discussed here briefly.
Definition of ions:
An ion is an electrically charged monoatomic or polyatomic chemical species.
An ion is formed from a chemical species that, following a chemical phenomenon (reaction) or a physical phenomenon (mechanical friction, radiation) loses or gains one or more electrons.
Classification of ions?
Ions are classified as :
Cations and anions:
There are different types of ions:
- Positive ions called cations that form by losing electrons
Examples: H + , Cu 2+ , NH 4+
- Negative ions called anions that form by gaining electrons
Examples: OH – , S 2- , HCOO –
Electrical neutrality of matter:
At the macroscopic scale (human scale) the liquid or solid material is always electrically neutral, which implies that an ionic material is always composed of cations and anions which compose their electric charge.
This neutrality makes it possible to predict the proportion of cations and anions.
Sodium chloride contains as many chloride ions (Cl-) as sodium ions (Na +) because each carries only one charge.
Aluminum chloride has three times more chloride ions (Cl-) than aluminum ions (Al3 +) because it is necessary to combine three ions chloure to offset the load carried by an aluminum ion.
Electronic structure of monoatomic ions:
Since an ion is formed by losing or gaining electrons, its electron structure is different from that of the starting atom, but it can be deduced from the ion formula:
- The ion formula indicates how it formed. For example an exponent 2+ indicates that there has been a loss of two electrons, an exponent – indicates that there has been an electron gain.
- It is necessary to resume the electronic structure of the initial atom and add or remove the electrons gained or lost from the last layer.
Example: electronic structure of the ion Al 3+
The formula Al 3+ indicates that the aluminum ion formed by losing electrons 3
The electronic structure of the aluminum atom of atomic number 13 is (K) 2 ( L) 8 (M) 3 .
If you remove 3 electrons from the last layer, then the layer M that initially contained 3 electrons becomes empty and it is no longer necessary to write it.
The electronic configuration of the aluminum atom is (K) 2 (L) 8 .
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