A hollow area in sediment in the shape of an organism or part of an organism is

• a cast
• a mold
• a trace fossil
• a petrified fossil

A solid copy of the shape of an organism is

• a mold
• a carbon film
• a cast
• a fossil record

What type of fossils provide evidence of the activities of ancient organisms?

• molds and casts
• petrified fossils
• trace fossils
• carbon films

Which of the following substances is not able to preserve entire organisms?

• sticky tar
• water
• amber
• ice

The term geologist is used to identify a scientist who studies fossils.

• True
• False

The number of years that have passed since the rock formed is the rock’s

• relative age
• law of superposition
• absolute age
• index fossil

The rate of decay of any radioactive element changes frequently.

• True
• False

Radioactive elements occur naturally in sedimentary rocks.

• True
• False

Geologists use radioactive dating to determine the absolute ages of rocks.

• True
• False

Radioactive decay is the time it takes for half of the radioactive atoms in an element to decay.

• True
• False