Which of the following is the correct sequence of the noble gases in their group in the periodic table

Modern Periodic law states that “the physical and chemical properties of the elements are periodic functions of their atomic numbers”. When atomic number is taken as fundamental property then abnormalities...

(i) Different elements discovered in different times were found to possess different physical and chemical properties. But, it was difficult to study all the information or properties of these elements....

Correct sequence – (c), (e), (d), (b), (a).

Mendeleev’s Periodic Table Modern Periodic Table Mendeleev's periodic table is based on atomic mass. Elements are arranged in increasing order of their atomic masses. Modern periodic table is based on atomic number. Elements are arranged...

Mendeleev’s periodic table                                      Modern periodic table.                ...

Modern Periodic Law states that properties of elements are a periodic function of their atomic number.  In Modern Periodic Table there are18 groups and 7 periods.

(d) Electronic configuration of He is 1s2

(a) Ionisation energy decreases as we move away from nucleus due to less electrostatic attraction between electrons and nucleus

(b) Noble gases exhibit low chemical activity

(c) He is obtained during radioactive decay