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Given the % abundance of isotopes, find the average atomic mass
easy and medium questions

Grade 10 SABIS

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Easy Level Questions:

  1. Element X has two isotopes, Isotope A with a mass of 15 and an abundance of 25%, and Isotope B with a mass of 18 and an abundance of 75%. What is the average atomic mass of Element X?

Answer: The average atomic mass of Element X can be calculated as (15 * 0.25) + (18 * 0.75) = 16.75.

  1. Element Y has three isotopes, Isotope P with a mass of 12 and an abundance of 40%, Isotope Q with a mass of 14 and an abundance of 20%, and Isotope R with a mass of 16 and an abundance of 40%. Calculate the average atomic mass of Element Y.

Answer: The average atomic mass of Element Y can be calculated as (12 * 0.40) + (14 * 0.20) + (16 * 0.40) = 13.6.

  1. Element Z has two isotopes, Isotope M with a mass of 16 and an abundance of 60%, and Isotope N with a mass of 18 and an abundance of 40%. Determine the average atomic mass of Element Z.

Answer: The average atomic mass of Element Z can be calculated as (16 * 0.60) + (18 * 0.40) = 16.4.

Medium Difficulty Questions:

  1. Element A has three isotopes, Isotope X with a mass of 10 and an abundance of 30%, Isotope Y with a mass of 12 and an abundance of 50%, and Isotope Z with a mass of 14 and an abundance of 20%. Calculate the average atomic mass of Element A.

Answer: The average atomic mass of Element A can be calculated as (10 * 0.30) + (12 * 0.50) + (14 * 0.20) = 11.8.

  1. Element B has four isotopes, Isotope P with a mass of 16 and an abundance of 25%, Isotope Q with a mass of 18 and an abundance of 35%, Isotope R with a mass of 20 and an abundance of 30%, and Isotope S with a mass of 22 and an abundance of 10%. Find the average atomic mass of Element B.

Answer: The average atomic mass of Element B can be calculated as (16 * 0.25) + (18 * 0.35) + (20 * 0.30) + (22 * 0.10) = 18.1.

  1. Element C has three isotopes, Isotope M with a mass of 24 and an abundance of 45%, Isotope N with a mass of 26 and an abundance of 25%, and Isotope O with a mass of 28 and an abundance of 30%. Determine the average atomic mass of Element C.

Answer: The average atomic mass of Element C can be calculated as (24 * 0.45) + (26 * 0.25) + (28 * 0.30) = 25.5.

These answers provide the calculated average atomic masses for the given elements based on the percentage abundances of their isotopes.

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