A Pure Sample of ²²⁶Ra Contains 1

question 59

Multiple Choice

A pure sample of ²²⁶Ra contains 1.5 × 10¹³ atoms of the isotope.If the half-life of ²²⁶Ra = 1.6 × 10³ years,what is the decay rate of this sample? (1 Ci = 3.7 × 10¹⁰ decays/s)

• A)8.0E-9 Ci
• B)2.1E+2 Ci
• C)5.6E-9 Ci
• D)1.8E-1 Ci
• E)​2.5E-1 Ci

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Definitions:

Amino Acids

Organic compounds serving as the building blocks of proteins, containing both amino and carboxylic acid functional groups.

Tidal Flat

A flat, muddy area of land that is covered and uncovered by the sea at high and low tides, respectively.

Clay Particles

The fine-grained mineral components of clay, usually less than 2 micrometers in size, contributing to its unique properties such as plasticity when wet.

Stromatolites

Layered structures formed by the growth of microorganisms in shallow water, representing some of the oldest fossils, dating back to over 3.5 billion years ago.