The properties of elements of a sub-group table are better predicted by their atomic
resemble each other more markedly than numbers than their atomic weights.
the properties of those between the Law of Modern Periodic Table states that
elements of the two sub-groups. properties of elements are the periodic
function of their atomic numbers. In the
Modern Periodic Table modern periodic table, elements are
arranged in order of their increasing
The vertical columns are known as
Groups and horizontal columns are
known as Periods; in the Modern
In 1913 Sir Henry Moseley discovered There are 18 groups and 7 periods in the
that elements positions in the periodic modern periodic table.
Long Form of Periodic Table
This periodic table is based on the electronic configuration of elements.
There are 118 elements have been identified.
A block of the periodic table of elements is a set of adjacent groups.
The respective highest-energy electrons in each element in a block belong to the same atomic
orbital type. Each block is named after its characteristic orbital; thus, the blocks are: s-block, p-
block, d-block and f-block