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medium difficulty easy examples for Given the average atomic mass of an element, find the % abundance of its isotopes

Grade 10 SABIS

Example 1: Average atomic mass: 32.7 Isotope A mass: 31 Isotope B mass: 34

To find the percentage abundance: Let's assume the abundance of Isotope A is x, and the abundance of Isotope B is y.

Equation 1: (x * 31) + (y * 34) = 32.7 Equation 2: x + y = 100

Solving the equations, we find that x = 70 and y = 30.

Answer: Isotope A: 70% abundance Isotope B: 30% abundance

Example 2: Average atomic mass: 42.9 Isotope A mass: 42 Isotope B mass: 44

To find the percentage abundance: Let's assume the abundance of Isotope A is x, and the abundance of Isotope B is y.

Equation 1: (x * 42) + (y * 44) = 42.9 Equation 2: x + y = 100

Solving the equations, we find that x = 60 and y = 40.

Answer: Isotope A: 60% abundance Isotope B: 40% abundance

Example 3: Average atomic mass: 56.4 Isotope A mass: 55 Isotope B mass: 58

To find the percentage abundance: Let's assume the abundance of Isotope A is x, and the abundance of Isotope B is y.

Equation 1: (x * 55) + (y * 58) = 56.4 Equation 2: x + y = 100

Solving the equations, we find that x ≈ 62.15 and y ≈ 37.85 (rounded to two decimal places).

Answer: Isotope A: Approximately 62.15% abundance Isotope B: Approximately 37.85% abundance

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