The periodic table is divided into 18 group. A group refers to a column of elements in the periodic table. All the elements in the same group share the same chemical and physical properties. Some of the groups are given specific names while the rest are identified by the first element in that group. The groups with specific names are as follows: Group 1: Alkali metals Group 2: Alkali earth metals Group 11: Coinage metals Group 15: Pnictogen Group 16: Chalcogens Group 17: Halogens Group 18: Noble gases.
Elements of section s: are those elements whose valence shells are s¹ or s².
This section includes group 1 and 2.
Group 1: Alkalyne metals (Li, Na, K, Rb, Cs, Fr): react violently with water.
Group 2. Alkalyne earth metals (Be, Mg, Ca, Sr, Ba, Ra: react less violently with water.
Elements of both group 1 and group 2 shine, are conductive and are malleable and ductile.
Elements of section p: are those elements whose valence shells are p¹, or p², or p³, or p⁴, or p⁵, or p⁶.
This section includes the groups 13, 14, 15, 16, 17 and 18.
Most of those elements and non-metals except for B, Si, Ge, As, Sb, Te and Po which are metalloids (they have some characteristics of metals and some characteristics of non-metal).
Non metals are brittle and poor conductive.
Elements of section d is the biggest group. These are transition metals. In this group the electrons fill the type d orbitals.
This section includes groups 3 through 12.
The properties of these elements are those of metals: high conductivitiy, mallability and electrical conductivity.
Elements of section f are other transition metals (inner transition metals). They partially fill some f orbitals.
A chemical reaction refers to an interaction between two or more chemical species that leads to the formation of other new chemical species.
There are many types of chemical reactions. The type shown above is called a double replacement reaction. In this type of reaction, ions exchange partners in the product.
A chemical reaction is said to be balanced when the number of atoms of each element on the left hand and right hand sides of the reaction equation are exactly the same.
