Morvant Laventille Secondary
Form 3 Integrated Science Notes
Topic: Ion Formation
A neutral atom has an equal number of proton and electron. Many neutral atoms however
lose or gain one or more electrons to form ions. All ions have a net negative or positive charge.
The ion that is formed when a neutral atom loses one or more electrons is called a positive
ion or a cation.
The ion that is formed when a neutral atom gains one or more electrons is called a negative
ion or anion.
Page 1
.
Hydrogen Ion Formation
.
Oxide (Oxygen) Ion Formation
.
Chloride Ion Formation
Ions Formed By Groups Of Atoms
Positive and negative can also be formed from groups of atoms instead of single atoms. For
example, the ammonium ion (NH4+) is a positive ion formed from a group hydrogen and
nitrogen atoms.
.
Ammonium ion
Page 2
Table Showing Some Common Ions Formed By Single Atoms
Charge Of Ion
+1
+2
+3
-1
-2
Name Of Ion
Symbol Of Ion
Hydrogen
Lithium
Potassium
Sodium
Silver
Copper(I)
Copper(ii)
Calcium
Magnesium
Lead
Barium
Iron(II)
Iron (III)
Aluminium
Chromium
Chloride
Bromide
Iodide
Oxide
Sulphide
H+
Li+
K+
Na+
Ag+
Cu+
Cu2+
Ca2+
Mg2+
Pb2+
Ba2+
Fe2+
Fe3+
Al3+
Cr3+
ClBrIO2S2-
Number of Electrons
Lost Or Gain By
Neutral Atom
Lost one (1) electron
Lost two (2) electrons
Lost three (3)
electrons
Gain one (1) electron
Gain two (2) electrons
Table Showing Some Common Ions Formed By Groups Of Atoms
Charge Of Ion
+1
-1
-1
-1
-1
-2
-2
-2
Name Of Ion
Ammonium
Hydroxide
Nitrite
Nitrate
Hydrogen Carbonate
Sulphite
Sulphate
Carbonate
Symbol Of Ion
NH4+
OHNO2NO3HCO3SO32SO42CO32-
Video Links
1 https://www.youtube.com/watch?v=aqeTytobnud Cations & Anions For Kids
2 https://www.youtube.com/watch?v=PCZtnbxtXqE Formation Of Ions
3 https://www.youtube.com/watch?v=x4IoMrlths0 Atoms Form Ions
End Of Notes
Page 3