Question

State two reasons for rejecting law of octaves

Answer 1

Limitations of law of octaves: The law of octaves has the following limitations ;

(A) The law of octaves was found to be applicable only upto calcium. It was not applicable to elements of higher atomic masses.

(B) Position of hydrogen along with fluorine and chlorine was not justified on the basis of chemical properties.

(C) Newlands placed two elements in the same slot to fit elements in the table. He also placed some unlike elements under the same slot. For example, cobalt and nickel are placed in the same slot and in the column of fluorine, chlorine and bromine. But cobalt and nickel have properties quite different from fluorine, chlorine and bromine. Similarly, iron which has resemblances with cobalt and nickel in its properties has been placed for away from these elements.

Thus, it was realized that Newlands’ law of octaves worked well only with lighter elements. Therefore, this classification was rejected.

Answer 2

The Law of OCTAVES was rejected for ;

° The law was only applicable upto the element CALCIUM ( 20).

° Newly discovered elements doesn't fit in this law of OCTAVES.

° Also when elements were arranged in order of increasing atomic masses, then this law was unsuccessful for heavier elements.