Ch.19 - Nuclear ChemistryWorksheetSee all chapters
All Chapters
Ch.1 - Intro to General Chemistry
Ch.2 - Atoms & Elements
Ch.3 - Chemical Reactions
BONUS: Lab Techniques and Procedures
BONUS: Mathematical Operations and Functions
Ch.4 - Chemical Quantities & Aqueous Reactions
Ch.5 - Gases
Ch.6 - Thermochemistry
Ch.7 - Quantum Mechanics
Ch.8 - Periodic Properties of the Elements
Ch.9 - Bonding & Molecular Structure
Ch.10 - Molecular Shapes & Valence Bond Theory
Ch.11 - Liquids, Solids & Intermolecular Forces
Ch.12 - Solutions
Ch.13 - Chemical Kinetics
Ch.14 - Chemical Equilibrium
Ch.15 - Acid and Base Equilibrium
Ch.16 - Aqueous Equilibrium
Ch. 17 - Chemical Thermodynamics
Ch.18 - Electrochemistry
Ch.19 - Nuclear Chemistry
Ch.20 - Organic Chemistry
Ch.22 - Chemistry of the Nonmetals
Ch.23 - Transition Metals and Coordination Compounds

Solution: When a 2.50 g sample of cobalt-60 is stored for 10 years, 0.669 g remain. What is the half-life of cobalt-60? a) 26.3 yb) 12.1 yc) 11.5 yd) 2.59 ye) 5.25 y 

Solution: When a 2.50 g sample of cobalt-60 is stored for 10 years, 0.669 g remain. What is the half-life of cobalt-60? a) 26.3 yb) 12.1 yc) 11.5 yd) 2.59 ye) 5.25 y 

Problem

When a 2.50 g sample of cobalt-60 is stored for 10 years, 0.669 g remain. What is the half-life of cobalt-60?

 

a) 26.3 y

b) 12.1 y

c) 11.5 y

d) 2.59 y

e) 5.25 y 

Solution

We’re being asked to determine the half-life of cobalt–60


Recall that half-life is the time needed for the amount of a reactant to decrease by 50% or one-half


The half-life of a first-order reaction is given by:



where:

t1/2 = half-life

k = decay constant


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