The Observational Fact About a Cepheid Variable Star That Leads

question 123

Multiple Choice

The observational fact about a Cepheid variable star that leads to a measurement of its distance from us is that its period of variation is directly related to its:

• A) surface temperature.
• B) position along the spiral arms of a galaxy.
• C) apparent magnitude.
• D) absolute magnitude.

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Definitions:

Electrons

Subatomic particles with a negative charge, found in electron shells surrounding the nucleus of an atom.

Benzene

A colorless, volatile liquid hydrocarbon present in coal tar and petroleum, used in chemical synthesis.

Resonance Structures

Representations of a molecule where the chemical connectivity is the same but the electrons are distributed differently around the structure.

Cyclic

Pertaining to chemical compounds that contain a ring structure within their molecules.