The isotope 
has a half-life of 7.5 seconds. If a sample contains 144 atoms of 
, approximately how many such atoms were present 30 seconds earlier?
Definitions:
Precious Moments
A brand known for its collectible porcelain figurines, gifts, and ornaments that often commemorates sweet, sentimental moments.
Timing
The selection of an appropriate or opportune moment to execute an action, often critical in contexts such as market entry, product launches, or investments.
Markdowns
Reductions in the selling price of goods, often to clear old stock or boost sales.
Valuable Selling Space
Prime retail or commercial area within a store or market that is strategically used to display and sell products to maximize customer purchases.
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