Average Atomic Mass Calculation Quiz

Average Atomic Mass Calculation

• Average atomic mass is calculated using the abundance and mass of isotopes.
• Formula: ((\text{abundance}_1 \times \text{mass}_1 + \text{abundance}_2 \times \text{mass}_2 + ... ) / 100)

Lithium (Li)

• Isotopes: 6Li (7.5% abundance, 6.0151223 amu) and 7Li (92.5% abundance, 7.0160041 amu)
• Calculation:
  • ( (7.5 \times 6.0151223) + (92.5 \times 7.0160041) / 100 = 6.94 ) amu
• Result: Average atomic mass of Li = 6.94 amu

Boron (B)

• Isotopes: 10B (19.9% abundance, 10.0129371 amu) and 11B (80.1% abundance, 11.0093055 amu)
• Calculation:
  • ( (19.9 \times 10.0129371) + (80.1 \times 11.0093055) / 100 = 10.81 ) amu
• Result: Average atomic mass of B = 10.81 amu

Chlorine (Cl)

• Isotopes: 35Cl (75.78% abundance, 34.96885271 amu) and 37Cl (24.22% abundance, 36.96590260 amu)
• Calculation:
  • ( (75.78 \times 34.96885271) + (24.22 \times 36.965902060) / 100 = 35.45 ) amu
• Result: Average atomic mass of Cl = 35.45 amu

Magnesium (Mg)

• Isotopes: 24Mg (78.99% abundance, 23.9850419 amu), 25Mg (10.00% abundance, 24.9858370 amu), and 26Mg (11.01% abundance, 25.9825930 amu)
• Calculation:
  • ( (78.99 \times 23.9850419) + (10.00 \times 24.9858370) + (11.01 \times 25.9825930) / 100 = 24.3 ) amu
• Result: Average atomic mass of Mg = 24.3 amu