### E3

Posted:

**Mon Oct 08, 2018 12:45 pm**I don't understand how to set up an equation for this exercise. Do I find the molar ratio between the two atoms?

Created by Dr. Laurence Lavelle

https://lavelle.chem.ucla.edu/forum/

https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=26&t=33304

Page **1** of **1**

Posted: **Mon Oct 08, 2018 12:45 pm**

I don't understand how to set up an equation for this exercise. Do I find the molar ratio between the two atoms?

Posted: **Mon Oct 08, 2018 2:41 pm**

That's pretty much it! The question is asking you to balance the weight of both sides of the scale. Assuming that the question is asking you to balance the 9 atoms of gallium (MM 70) with an x number of astatine (MM 210), you could set up the ratio equation 9/70=x/210 and cross multiply to get x=3.