Question

Elements A and B are following Newland's law of octaves. The number of elements lying between A and B is ‘x’. The atomic mass of A is ‘y’ and the atomic mass of B is thrice the atomic mass of A. If 2x + 3y = 60 then find the atomic mass of A and B.

• A. A = 16; B = 48
• B. A = 30; B = 90
• C. A = 15; B = 45
  
• D. A = 6; B = 56

Answer 1

The correct option is A A = 16; B = 48

According to the law of octaves, when elements are arranged in the order of increasing atomic mass, the properties of every 8th element are similar to that of the 1st element.

Thus there are 6 elements in between two elements following Newlands’ law of octaves.

Here x = 6,
So,
2x + 3y = 60
=> 2 x 6 + 3y = 60
=> y = 16
Therefore, the atomic mass of A is 16 and the atomic mass of B is (16 x 3) = 48.