Question 3
What is the basic difference in approach between the Mendeleev’s Periodic Law and the Modern Periodic Law?
A Russian chemist, Dmitri Mendeleev was the first to develop a periodic table & he gave a law called Mendeleev periodic law which states that the physical & chemical properties of the elements are a periodic function of their atomic masses. In his periodic table the elements are arranged in vertical rows called groups & horizontal rows known as periods.There are nine groups & seven periods. He arranged only 60 elements in periodic table
A English physicist Moseley, in 1913 gave amodern periodic law which states that the physical & chemical properties of the elements are the periodic function of their atomic number.This law becomes the base of modern periodic law.In modern periodic table there are 18 groups & 7 periods.
