Question

How are elements in the same group similar?

Answer 1

Hint Periodic made the study of elements and their properties easy. Periodic table made the study of the chemistry of elements. The elements in the modern periodic table are arranged on the basis of atomic number.

Complete answer:
The periodic table was discovered by Dmitri Mendeleev in 1869. Periodic table contains 118 elements. Mendeleev law states that "The properties of the elements are the periodic function of their atomic number", so elements in the periodic table are arranged on the basis of atomic number. We know that there are in total 7 periods and 18 groups. Periodic tables made the study of elements and their properties easy. The factor that made it easy to study properties of the elements down the group, the properties of elements of a group follows the same trend.
Now let's see the main factor that is responsible for this:
Valence electrons are the electrons present in the outermost shell of an atom. The valence electrons can easily react with the electrons in the outermost shell of another atom. The elements of the same group have the same number of valence electrons. The electrons in the outermost shell either lose or gain electrons and form bonds with other atoms. The atoms either lose or gain electrons only in order to attain the stable state or complete its octet, this property is responsible for formation of compounds and the reactivity of an element. Since the elements of a particular group have the same valence electron so, the type of compound, reactivity, ionization energy, atomic radius everything will be the same. Hence exhibit similar properties.

Note: All the elements in all groups won't show similar properties that are in certain groups, all elements won't have the same valence electrons. Hence won't show similar properties as shown by other elements of the group. Due to this there may be variation in all aspects like ionization energy, atomic radius, reactivity etc.