Potassium ion is present in foods and is an essential nutrient in the human body. One of the naturally occurring isotopes of potassium, potassium-40, is radioactive. Potassium-40 has a natural abundance of 0.0117% and a half-life of 1.28 x 10° yr. It undergoes radioactive decay in three ways: 98.2% is by electron capture, 1.35% is by beta emission, and 0.49% is by positron emission. 1. Write the nuclear equations for the three modes by which K-40 decays. 2. How many K-40 ions are present in 0.76 g of KBr? 3. How long does it take for 7.65% of K-40 in 0.76 g of KBr to undergo radioactive decay?

Potassium ion is present in foods and is an essential nutrient in the human body. One of the naturally occurring isotopes of potassium, potassium-40, is radioactive. Potassium-40 has a natural abundance of 0.0117% and a half-life of 1.28 x 10° yr. It undergoes radioactive decay in three ways: 98.2% is by electron capture, 1.35% is by beta emission, and 0.49% is by positron emission. 1. Write the nuclear equations for the three modes by which K-40 decays. 2. How many K-40 ions are present in 0.76 g of KBr? 3. How long does it take for 7.65% of K-40 in 0.76 g of KBr to undergo radioactive decay?

Chemistry

10th Edition

ISBN:9781305957404

Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Chapter1: Chemical Foundations

Section: Chapter Questions

Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...

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