Question

Elements a, b and c form a dobereiner traid if atomic mass of element a is 7 and that of c is 39 what is the atomic mass of the element by

Answer 1

element a is Lithium (7)
element c is potassium (39)
then, 7+39/2 =23
element b is sodium (23)

Answer 2

Answer:

your answer is 23

Explanation:

:7+39 =46

:46/2=23