Chapter 21.8, Problem 3PPA

Interpretation Introduction

Interpretation: The concentration of Rn-222 in the basement of a house is $\text{1}{\text{.8×10}}^{\text{-6}}$ mol/L. When the air remains static, the concentration of the radon after 2.4 days should be determined.

Concept Introduction:

•   Half-life ( ${\text{t}}_{\frac{\text{1}}{\text{2}}}$) is the time required for a quantity to reduce to half its initial value..
• An unstable nucleus emits radiation spontaneously to become stable nuclei by losing energy. This process of emission of radiation by unstable nuclei is known as radioactive decay.
• In general the substance left after n half –lives is ${\left(\frac{\text{1}}{\text{2}}\right)}^{\text{n}}$.
•      $\text{n}\text{=}\frac{\text{Given}\text{days to needed to}\text{reduce}\text{the concentration of the substance}}{\text{Half-life}\text{of}\text{the}\text{given}\text{substance}}$
• To determine: The n days required to reduce the concentration of  the given Rn-222.