State the modern periodic law.

State Modern periodic law.

As per the modern periodic law the physical and chemical properties function of their

(a) The modern periodic table has been evolved through the early attempts of Dobereiner, Newland and Mendeleev. List one advantage and one limitation of all the three attempts. (b) Name the scientist who first of all showed that atomic number of an element is a more fundamental property than its atomic mass. State Modern periodic law.

In the modern periodic table, the elements are arranged in the increasing order of their atomic number. This arrangement is based on the modern periodic law, which states that the properties of elements are a periodic function of their atomic numbers. In the modern periodic table, each column is called a group and each row is called a period. Elements within the same group show similarity and gradation in properties. This is due to the same number of electroms in the outermost shell . Based on the above paragraph, answer the following question: How many groups are there in the modern periodic table?