Chemistry

Problem

Element Y has two stable isotopes:

^{63}\text{Y}

with a mass of 62.9296 u and

^{65}\text{Y}

with a mass of 64.9278 u. The isotopes occur in a ratio of 3 atoms of

^{63}\text{Y}

for every 2 atoms of

^{65}\text{Y}

. Determine the average atomic mass of element Y to four significant figures.