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%

I think I worked this yesterday. Let me know if this is not the same problem.

http://www.jiskha.com/display.cgi?id=1418542095

To calculate the closest percent abundance of Magnesium-26, we need to compare the atomic masses and abundances of Magnesium-24, Magnesium-25, and Magnesium-26.

Given:
- Magnesium-24 has an atomic mass of 23.9850 amu and an abundance of 78.99%.
- Magnesium-25 has an atomic mass of 24.9858 amu.
- Magnesium-26 has an atomic mass of 25.9826 amu.

We want to calculate the percent abundance of Magnesium-26. Here's how to do it:

Step 1: Determine the contribution of Magnesium-26 to the average atomic mass.
We know the atomic masses and abundances of Magnesium-24 and Magnesium-25. To calculate the contribution of Magnesium-26, we subtract the contributions of Magnesium-24 and Magnesium-25 from the average atomic mass.

Average atomic mass = (Mass of Magnesium-24 * Abundance of Magnesium-24) + (Mass of Magnesium-25 * Abundance of Magnesium-25) + (Mass of Magnesium-26 * Abundance of Magnesium-26)

Using the average atomic mass from the periodic table, we subtract the contributions of Magnesium-24 and Magnesium-25:
Average atomic mass - (Mass of Magnesium-24 * Abundance of Magnesium-24) - (Mass of Magnesium-25 * Abundance of Magnesium-25) = Mass of Magnesium-26 * Abundance of Magnesium-26

Step 2: Solve for the Abundance of Magnesium-26.
Now we can solve for the Abundance of Magnesium-26 by rearranging the equation from Step 1:

Abundance of Magnesium-26 = (Average atomic mass - (Mass of Magnesium-24 * Abundance of Magnesium-24) - (Mass of Magnesium-25 * Abundance of Magnesium-25)) / Mass of Magnesium-26

Plugging in the values we have:
Abundance of Magnesium-26 = (average atomic mass - (23.9850 amu * 78.99%) - (24.9858 amu * 0%)) / 25.9826 amu

Now, calculate the percentage by multiplying the Abundance of Magnesium-26 by 100%:

Percent abundance of Magnesium-26 = Abundance of Magnesium-26 * 100%

Using the given average atomic mass, calculate the closest percent abundance from the options provided (a, b, c, d, or e).