Question

write short note : position of isotopes in mendeleev or modern periodic table​

Answer 1

Isotopes: Isotopes are the atoms having the same atomic number but different atomic masses. Therefore, according to Mendeleev's classification, these should be placed at different places depending upon their atomic masses. For example, hydrogen isotopes with atomic masses 1,2 and 3 should be placed at three places.

Answer 2

Explanation:

Question :-

write short note : position of isotopes in mendeleev or modern periodic table.

Answer :-

1. Isotopes were discovered long time after Mendeleev developed the periodic table.

2. All isotopes of the same element have different atomic masses but same atomic number. They also have the same chemical properties.

3. In Mendeleev's periodic table, elements are arranged in increasing order of their atomic masses such that chemically similar elements are placed together in a group. So, it was difficult to place them in Mendeleev's periodic table.

4. In modern periodic table, elements are arranged in increasing order of their atomic numbers. Hence, all the isotopes of an element occupy the same position in the modern periodic table. iv. ement.