Question

1. Naturally occurring europium (Eu) consists of two isotopes was a mass of 151 and 153. Europium- 151 has an abundance of 48.03% and Europium-153 has an abundance of 51.97%. What is the atomic mass of europium?​

Answer 1

The atomic mass of Europium is 152 amu

Work:
151(0.4803) = 72.52 amu
153(0.5197) = 79.5 amu
72.5 + 79.5 = 152 amu

Answer 2

34 percent would mean sudden and careful passing