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:

Muscle Contraction

The process by which muscle fibers produce force and tension through the sliding of actin and myosin filaments, powered by ATP.

Nuclear Envelope

The double membrane structure that surrounds the nucleus in eukaryotic cells, controlling the flow of substances in and out of the nucleus.

Lipid Bilayers

Thin polar membrane made of two layers of lipid molecules. These layers are fundamental in the structure of cell membranes, providing barriers and pathways for substances.

Microfilaments

Fine, thread-like protein fibers, predominantly actin, that are part of the cytoskeleton in eukaryotic cells.