Explanation:
Elements which belong to same group show similar chemical properties.
This is because elements that lie in the same group have same number of valence electrons. Hence, they tend to show same type of reactivity which makes them exhibit similar chemical properties.
As chemical properties are defined as the properties which tend to show difference in chemical composition of a substance.
For example, toxicity, reactivity, combustion etc are all chemical properties.
Thus, we can conclude that group is the term used to describe a set of elements whose properties tend to be largely predictable based on position on the periodic table.
