What Factors Are Important When Trying to Classify a Spiral

question 97

Multiple Choice

What factors are important when trying to classify a spiral galaxy?

• A) amount of dust and gas in the galaxy
• B) structure of the spiral arms
• C) size of the central region
• D) All of the these are important.

---

Definitions:

TSCA

The Toxic Substances Control Act, a United States law passed by Congress in 1976 designed to regulate the introduction of new or already existing chemicals.

Premanufacturing Notice

A requirement under environmental law for manufacturers to notify a government agency before producing or importing new chemicals.

EPA

The Environmental Protection Agency, which focuses on the conservation of the environment and protecting human health through the enforcement of regulations.

Superfund

A federal program established to fund the cleanup of sites contaminated with hazardous substances and pollutants.