Question 15.
Write short notes.
Position of isotopes in the Mendeleev’s and the modern periodic table.
Answer:
Isotopes - In certain elements, some atoms have the same atomic number but different atomic mass number. Such atoms of an element are called isotopes of that element.
⇒ Isotopes were discovered long time after the Mendeleev discovered periodic table.
⇒ As we know that the isotopes have different atomic masses but same chemical properties.
⇒ Thus, the isotopes of element are placed in the same place of that of the element instead of been given different place in modern periodic table for each isotope.
