9. the element copper has naturally occurring isotopes with mass numbers of 63 and 65. the relative…

9. the element copper has naturally occurring isotopes with mass numbers of 63 and 65. the relative abundance and atomic masses are 69.2% for mass = 62.93 amu, and 30.8% for mass = 64.93 amu. calculate the average atomic mass of copper.\n10. calculate the atomic mass of bromine. the two isotopes of bromine have atomic masses and relative abundance of 78.92 amu (50.69%) and 80.92 amu (49.31%).

9. the element copper has naturally occurring isotopes with mass numbers of 63 and 65. the relative abundance and atomic masses are 69.2% for mass = 62.93 amu, and 30.8% for mass = 64.93 amu. calculate the average atomic mass of copper.\n10. calculate the atomic mass of bromine. the two isotopes of bromine have atomic masses and relative abundance of 78.92 amu (50.69%) and 80.92 amu (49.31%).

Answer

Explanation:

Step1: Convert percentages to decimals

69.2% = 0.692, 30.8% = 0.308

Step2: Calculate contribution of each isotope

(62.93 amu × 0.692) + (64.93 amu × 0.308) ≈ 43.55 amu + 20.00 amu = 63.55 amu

Step3: Convert percentages to decimals for Br

50.69% = 0.5069, 49.31% = 0.4931

Step4: Calculate contribution of each Br isotope

(78.92 amu × 0.5069) + (80.92 amu × 0.4931) ≈ 40.00 amu + 39.90 amu = 79.90 amu

Answer:

  1. 63.55 amu
  2. 79.90 amu