Question

Naturally occurring magnesium consists of Magnesium-24 (23.9850 amu; 78.99%), Magnesium-25 (24.9858 amu), and Magnesium-26 (25.9826 amu). Using the average atomic mass from the periodic table, calculate the closest percent abundance of Magnesuim-26.
a) 29.30%
b) 8.993%
c) 10.10%
d) 11.71%
e) 9.500%

Answer 1

I think I worked this yesterday. Let me know if this is not the same problem.
http://www.jiskha.com/display.cgi?id=1418542095