Average Atomic Mass s2

Name:______Average Atomic Mass Calculate the mass of the following. 1. 9B (19.78%), 11B (80.22%) 2. 104Ag (51.72%), 109Ag (48.28%) 3. 112Sn (15.87%), 120Sn (80.53%), 124Sn (3.60%) 4. 24Mg(78.70%), 25Mg(10.13%), 26Mg(11.17%) 5. 69Ga(60.27%), 71Ga(39.73%) 6. Calculate the average atomic mass of rubidium if 72.17% of its atoms have a mass of 84.91amu and 27.83% of its atoms have a mass of 86.91amu. 7. Calculate the average atomic mass of chlorine if 75.77% of its atoms have a mass of 34.97amu and 24.23% of its atoms have a mass of 36.96amu. 8. The new element Creekium (Cc) was discovered in 1976 by Mr. Wells (who received his Noble Prize in Chemistry in 2006). It has three isotopes: Cc-284 (34.60%), Cc-285 (21.20%), and Cc-286 (44.20%). What is its average atomic mass? 9. Copper used in electric wires comes in two flavors (isotopes): 63Cu and 65Cu. 63Cu has an atomic mass of 62.9298 amu and an abundance of 69.09%. The other isotope, 65Cu, has an atomic mass of 65.1746 amu and an abundance of 30.91%. The average atomic mass between these two isotopes is 63.546amu. Calculate the average atomic mass of Cu. 10. Magnesium consists of three naturally occurring isotopes. The percent abundance of these isotopes is as follows: 24Mg (78.70%), 25Mg (10.13%), and 26Mg (11.7%). If the atomic mass of 24Mg is 23.87612amu, 25Mg is 24.98584 amu, and 26Mg is 25.98259 amu, calculate the average atomic mass of Mg.