Symbol is the shorthand abbreviation of the full name of an element.
Valency
Valency is the number of hydrogen atoms or the number of chlorine atoms or double the number of oxygen atoms with which one atom of that element combines. OR, The number of electrons lost, gained or shared with one atom of the element in order to acquire the stable configuration of the nearest inert gas element.
List of Cations or basic radicals:
Name
Symbol
Charge
Hydrogen
H+
+1
Lithium
Li+
+1
Sodium
Na+
+1
Potassium
K+
+1
Cuprous or Copper(I)
Cu+
+1
Silver
Ag+
+1
Aurous or Gold(I)
Au+
+1
Mercurous or mercury (I)
Hg2+2
+1
Ammonium
NH4+
+1
Phosphonium
PH4+
+1
Magnesium
Mg2+
+2
Calcium
Ca2+
+2
Barium
Ba2+
+2
Cupric or Copper(II)
Cu2+
+2
Mercuric or Mercury (II)
Hg2+
+2
Ferrous or Iron (II)
Fe2+
+2
Cobaltous or Cobalt(II)
Co2+
+2
Nickel
Ni2+
+2
Manganous or Manganese(II)
Mn2+
+2
Cadmium
Cd2+
+2
Zinc
Zn2+
+2
Plumbous or Lead(II)
Pb2+
+2
Stannous or Tin(II)
Sn2+
+2
Ferric or Iron(III)
Fe3+
+3
Manganic or Manganese(III)
Mn3+
+3
Aluminium
Al3+
+3
Auric or Gold(III)
Au3+
+3
Antimonous or Antimony(III)
Sb3+
+3
Arsenous or Arsenic(III)
As3+
+3
Chromium
Cr3+
+3
Cobaltic or Cobalt(III)
Co3+
+3
Platinic or Platinum(IV)
Pt4+
+4
Plumbic or Lead(IV)
Pb4+
+4
Stannic or Tin(IV)
Sn4+
+4
Arsenic(V)
As5+
+5
Antimonic or Antimony(V)
Sb5+
+5
List of variable valencies:
Element
Name
Symbol
Charge
Copper
Cuprous or Copper(I)
Cu+
+1
Cupric or Copper(II)
Cu2+
+2
Gold
Aurous or Gold(I)
Au+
+1
Auric or Gold(III)
Au3+
+3
Mercury
Mercurous or mercury (I)
Hg2+2
+1
Mercuric or Mercury (II)
Hg2+
+2
Cobalt
Cobaltous or Cobalt(II)
Co2+
+2
Cobaltic or Cobalt(III)
Co3+
+3
Lead
Plumbous or Lead(II)
Pb2+
+2
Plumbic or Lead(IV)
Pb4+
+4
Arsenic
Arsenous or Arsenic(III)
As3+
+3
Arsenic(V)
As5+
+5
Antimony
Antimonous or Antimony(III)
Sb3+
+3
Antimonic or Antimony(V)
Sb5+
+5
Tin
Stannous or Tin(II)
Sn2+
+2
Stannic or Tin(IV)
Sn4+
+4
Iron
Ferrous or Iron (II)
Fe2+
+2
Ferric or Iron(III)
Fe3+
+3
Manganese
Manganous or Manganese(II)
Mn2+
+2
Manganic or Manganese(III)
Mn3+
+3
List of anion or acidic radicals:
Name
Symbol
Charge
Acetate
CH3COO–
-1
Formate
HCOO–
-1
Bicarbonate or Hydrogen carbonate
HCO3–
-1
Bisulphate
HSO4–
-1
Bisulphite
HSO3–
-1
Bisulphide
HS–
-1
Fluoride
F–
-1
Chloride
Cl–
-1
Bromide
Br–
-1
Iodide
I–
-1
Hypochlorite
ClO–
-1
Hypobromite
BrO–
-1
Hypoiodite
IO–
-1
Chlorite
ClO2–
-1
Bromite
BrO2–
-1
Iodite
IO2–
-1
Chlorate
ClO3–
-1
Bromate
BrO3–
-1
Iodate
IO3–
-1
Perchlorate
ClO4–
-1
Perbromate
BrO4–
-1
Periodate
IO4–
-1
Nitrite
NO2–
-1
Nitrate
NO3–
-1
Hypophosphite
H2PO2–
-1
Biphosphate
H2PO4–
-1
Cyanide
CN–
-1
Cyanate
CNO–
-1
Thiocyanate
SCN–
-1
Permanganate
MnO4–
-1
Hydride
H–
-1
Hydroxide
OH–
-1
Superoxide
O2–
-1
Hydrogen peroxide
HO2–
-1
Carbonate
CO32-
-2
Chromate
CrO42-
-2
Dichromate
Cr2O72-
-2
Manganate
MnO42-
-2
Sulphide
S2-
-2
Sulphite
SO32-
-2
Thiosulphate
S2O32-
-2
Sulphate
SO42-
-2
Oxide
O2-
-2
Peroxide
O22-
-2
Stannite
SnO22-
-2
Stannate
SnO32-
-2
Silicate
SiO32-
-2
Oxalate
C2O42-
-2
Molybdate
MoO42-
-2
Plumbite
PbO22-
-2
Plumbate
PbO32-
-2
Zincate
ZnO22-
-2
Aluminate
AlO33-
-3
Arsenite
AsO33-
-3
Arsenate
AsO43-
-3
Boride
B3-
-3
Borate
BO33-
-3
Nitride
N3-
-3
Phosphide
P3-
-3
Phosphite
PO33-
-3
Phosphate
PO43-
-3
Ferricyanide
[Fe(CN)6]3-
-3
Ferrocyanide
[Fe(CN)6]4-
-4
Carbide
C4-
-4
Relative atomic mass:
Relative molecular mass:
% composition of an element:
Empirical formula: The simplest formula possible for any compound in which atoms of the constituent elements are in a simple whole-number ratio.
Molecular formula: The formula that shows the exact number of atoms of each of the constituent elements present in a molecule of any compound.
Practice Set-1
Find the empirical formula, molecular weight and empirical weight of the following-