Question

The atomic masses of three elements A, B and C having similar chemical properties are 7, 23 and 39, respectively.

1. Calculate the average atomic mass of elements A and C.
2. Compare the average atomic mass with atomic mass of B.
3. What could the elements A, B and C be?

Answer 1

(a) The average atomic mass of elements A and C = `(7+39)/2=46/2=23`

(b) The average atomic mass of elements A and C is equal to the atomic mass of element B.

(c) A is lithium, B is sodium and C is potassium.