HELP FAST PLEASE


Calculating Atomic Mass
1. Look at the data table. What do the numbers 6 and 7 in 6X and 7X represent?
______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
2. Look at step 1. What does amu stand for? What does it mean?
____________________________________________________________________________________________________________________________________________________________________
3. Look at step 2. Why is each isotope’s mass multiplied by the isotope’s percent abundance? ______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
4. In step 3, why isn’t the answer a whole number?
____________________________________________________________________________________________________________________________________________________________________
5. Assume that a new lithium isotope, 8Li, is identified. It is a trace isotope, meaning that it exists in a very tiny quantity. How will this discovery affect the atomic mass of lithium? ____________________________________________________________________________________________________________________________________________________________________
6. Calculate the atomic mass of the unknown element. Then identify the element.
Isotope
Mass (amu)
Percent abundance
185X
184.953
37.40
187X
186.956
62.60



7. Calculate the atomic mass of the unknown element. Then identify the element.
Isotope
Mass (amu)
Percent abundance
113X
112.904
4.30
115X
114.904
95.70