What are the merits and demerits of Newland 's classification?

Explanation

Merits
(a) This classification worked well for lighter elements only up to Ca.
(b) This classification gave us a relation between the properties of elements and their atomic masses.
(c) It was shown by this· classification for the first time. that there exists a periodicity in the propetties of the elements.
Demerits :
(a) This classification failed when the heavier elements beyond Ca were arranged according to Newlands law of octaves
(b) At the time ofthis law, noble gases were unknown. When noble gases, were discovered, neon (Ne) was placed between F and Na and argon (Ar) between Cl and K. so these became the ninth elements and not the eighth. which had similar properties.