Metals generally exhibit a valency of +1, +2, or +3, as they tend to lose one or more electrons to achieve a stable electron configuration. Alkali metals (like sodium and potassium) typically have a valency of +1, while alkaline earth metals (like magnesium and calcium) usually have a valency of +2. Transition metals can have multiple valencies, often ranging from +1 to +7, depending on the specific element and its chemical environment.
Valency, or the combining capacity of an element, can change across a period due to variations in the number of valence electrons. As you move from left to right across a period in the periodic table, elements typically gain more valence electrons, transitioning from metals to non-metals. This change influences their ability to form bonds, with metals often having low valency and non-metals having higher valency. Consequently, the types of chemical bonds and compounds that elements can form also vary across the period.
The easiest way to determine the valency of an atom is to locate its place on the periodic table. Generally, it is useful to remember that metals tend to give away valence electrons where non metal atoms tend to obtain them. For example, sodium, a metal, is in group 1 has valency of 1. Sulfur, a non metal, is in group 16 and is 2 electrons away from its stable electron configuration, hence it has valency of 2.
Group number 1 = Valency 1+group number 2 = valency 2+group number 3 = valency 3+group number 4 = valency 4+ and 4- (some cases) group number 5 = valency 3-group number 6 = valency 2-group number 7 = valency 1-group number 8 = valency 0For the transition elements they will either state Copper (III) Sulphate or it will be like Cu2(SO4)3You can find the valency by the base of sulphate and you know its positive because metals are always positive and are written in the left.Source: I am a GCE O Level Sciences Student (O2)
Transition metals
-3 to metals and hydrogen (phophide) +3 in oxo-compounds (phosphite) +5 in oxo-compounds (phosphate)
Out of the non-metals you listed, nitrogen (N) is the only one that does not exhibit variable valency. Zinc (Zn), copper (Cu), and iron (Fe) can exhibit variable valency in certain compounds.
Halogens are not like metals. Halogens are elements missing one electron for full valency.
Valency, or the combining capacity of an element, can change across a period due to variations in the number of valence electrons. As you move from left to right across a period in the periodic table, elements typically gain more valence electrons, transitioning from metals to non-metals. This change influences their ability to form bonds, with metals often having low valency and non-metals having higher valency. Consequently, the types of chemical bonds and compounds that elements can form also vary across the period.
The easiest way to determine the valency of an atom is to locate its place on the periodic table. Generally, it is useful to remember that metals tend to give away valence electrons where non metal atoms tend to obtain them. For example, sodium, a metal, is in group 1 has valency of 1. Sulfur, a non metal, is in group 16 and is 2 electrons away from its stable electron configuration, hence it has valency of 2.
S = +6 valency O = -2 valency
Both are transition metals and have a valency of 2.
Many metals, non-metals and semi-metals have variable valency= Eg= Metals = Iron(2,3) Manganese(2,4) Copper(1,2) Non-Metal = Sulfur(4,6) Carbon(2,4) Phosphorus(3,5) Semi-Metal= Silicon(2,4) Arsenic(3,5) Germanium(2,4)
The valency of a sulfate ion is -2, meaning it has a charge of -2 due to the presence of four oxygen atoms and a sulfur atom. This valency allows the sulfate ion to form compounds with metals and other ions through ionic bonding.
To find the valency number of an element, look at the group number on the periodic table. For main group elements (groups 1, 2, 13-18), the valency is the same as the group number. For transition metals, the valency can vary and is usually determined by the charge of the ion formed by the element.
Group number 1 = Valency 1+group number 2 = valency 2+group number 3 = valency 3+group number 4 = valency 4+ and 4- (some cases) group number 5 = valency 3-group number 6 = valency 2-group number 7 = valency 1-group number 8 = valency 0For the transition elements they will either state Copper (III) Sulphate or it will be like Cu2(SO4)3You can find the valency by the base of sulphate and you know its positive because metals are always positive and are written in the left.Source: I am a GCE O Level Sciences Student (O2)
Alkali metals have one electron in their valency shell whereas halogens have seven. By losing al electron to a halogen, both ions get a full set of electrons in their valency shell.
Generally non-metals gain electrons and form anions.