Question

Some one plzz help me tomorrow is my exam..
A,B and C are the elements of a dobereiner's traid. If the atomic mass of A is 7 and that of C is 39, what should be the atomic mass of B?

Answer 1

according to donbereiner's triad the atomic mass of element B will be the arithmetic mean of element A and C. i.e,

7+39÷2=23