CH. 6 Section 3 vocab. terms (by Hunter and Sawyer)

Front

Fossil formed when an organism dies, decays, and minerals fill the cavity, resulting in a ____ (mold fossil).

Back

cast

Front

Fossil formed when an organism dies, covered by sediment, decays, leaving a cavity.

Back

Mold

Front

Science of determining the order of past events without absolute age.

Back

Relative dating.

Front

Radiometric dating or ____________ is a technique to date materials like rocks or carbon using radioactive impurities.

Back

Radioactive dating

Front

_____________ is an element that spontaneously degenerates its nucleus, emitting alpha, beta, or gamma rays. Elements with atomic numbers > 83 are radioactive. Naturally occurring ____________ include radium, thorium, and uranium.

Back

radioactive element

Front

Time for a property (e.g., substance concentration) to reduce by half.

Back

half life

Front

Definition: No living members in a species or family.

Back

extinct

Front

Policy of gradual reform instead of sudden change.

Back

gradualism

Front

Formed when minerals replace part of an organism; water with dissolved minerals seeps through sediment to reach the dead organism, leaving hardened minerals after evaporation.

Back

petrified fossil

Front

Term for total discovered fossils and info derived from them.

Back

fossil record