Chapter 2 - Atoms, Molecules, and Ions - Questions and Exercises - Exercises - Page 84: 2.43

Atomic mass = 69.72 u The element is gallium (Ga).

Atomic mass of the element = $(\frac{60.11}{100}\times68.926u)+(\frac{39.89}{100}\times70.926u)$ = 69.72 u The element with atomic mass 69.72 u is gallium and its symbol is Ga (Refer Periodic Table)