What are ions?

2 Answers
Mar 3, 2018

See below.


Ions are atoms or molecules with a non-zero net charge. It could be positive or negative.

Number of electrons in an ion is not equal to number of protons.

If number of protons are more then that ion is cation ,if number of electrons are more than number of protons then is is an anion.

Example of cation #Na^+ , K^+,H_3 O^+#etc

Anion #-> CO_3^(2-), Cl^(-) , O^(2-)# etc.

Ions with more than one atom of element are called polyatomic ions .

Fact: Ions exist in water in equilibrium with water molecules.

There are several ways to form ions like disolving a salt (with ionic bond) in water and by passing electricity.

Mar 3, 2018

#"Ions are charged particles....."#


Ions can be atomic, i.e. #X^-#, or #Na^+#, or molecular, i.e. #SO_4^(2-)#, or #NO_3^(-)#...i.e. the singly-charged cations contain ONE electron less than the sum of the constituent atomic numbers, or ONE or more electrons for the anions. For compound ions such as nitrate, or sulfate. the electronic charge is presumed to lie on the most electronegative atom, i.e. on oxygen; of course resonance structures can be drawn.

And, so if we gots a representation of #Na^+#, or #Cl^-#, we know that for the sodium ion, while there are 11 charged nuclear particles (how do we know this?), there are 10 charged extranuclear particles, 10 electrons. And for chloride ion, while there are 18 charged extranuclear particles, 18 electrons, there are 17 nuclear particles of the OPPOSITE charge.

This is something to important to learn, because EVERY CHEMICAL REACTION conserves mass and charge.....