The Maximum Life Span of Humans

question 128

Multiple Choice

The maximum life span of humans:

• A)has increased over time.
• B)has not changed since the beginning of recorded history.
• C)has matched their life expectancy in recent times.
• D)is about 65 years as the first decade of the twenty-first century draws to a close.

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Definitions:

NonAromatic

Molecules or compounds that do not contain a ring of continuously overlapping p orbitals, thus lacking the stability associated with aromatic systems.

π Network

An extended system of π bonds in a molecule, which can involve multiple atoms contributing p orbitals for delocalized electron sharing.

Cyclobutadiene

A highly reactive, four-carbon cyclic diene that is unstable at room temperature, interesting for its peculiar electronic properties and symmetry.

1,3-Butadiene

A simple conjugated diene with the formula C4H6, important as a monomer in producing synthetic rubber.