A Sample Containing 4

question 79

Multiple Choice

A sample containing 4.0 × 10¹⁸ atoms of a radioactive isotope decays with a half-life of 2.3 years.How many undecayed atoms are left after 3.7 years?

• A)2.5 × 10¹⁸
• B)1.7 × 10¹⁸
• C)1.3 × 10¹⁸
• D)1.1 × 10¹⁸

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Definitions:

Combustion Engine

An engine that generates mechanical power by burning a fuel-air mixture to create an explosive reaction.

Hydrogen

A chemical element with the symbol H and atomic number 1, known as the lightest element in the universe and a primary component in water molecules.

Commercial Energy

Energy produced and sold for profit, including electricity, natural gas, and other fuels used in the industrial, commercial, and residential sectors.

Wasted

Resources or potential that is not effectively utilized or is discarded without beneficial use.