Similar Properties in Elements

Assertion: Elements belonging to the same group show similarity in chemical properties. Reason: Elements of the same group have same number of valence electrons.

What are the similarities in properties of elements in halogen family?

Lithium, sodium and potassium are placed in the same group on the basis of similar properties. List three similar properties of these elements.

Why do elements with similar properties occur in the same group?

Read the passage and answer the following questions. Mendeleev was a Russian chemist, who contributed the most for the development of periodic table of elements wherein the elements were arranged on the basis of their fundamental property, the atomic mass and also on the similarity of chemical properties. Only 63 elements were known at his time. He arranged the 63 elements in the increasing order of the.ir atomic masses and found that there was a periodic recurrence of elements with similar physical and chemical properties. He observed that elements with similar properties fall in the same vertical column. These vertical columns are called groups and horizontal rows of elements are called periods. Mendeleev predicted the existence of certain elements not known at that time and named two of them as Eka-silicon and Eka-aluminium. How many valence electrons are present in each one of them?

Elements beloging to the same group have similar properties because