Radioactive dating

The time it takes for half of a radioactive element's atoms to decay is its:

• Era
• Half life
• Relative age
• Absolute age

Index fossils are used to determine:

• How old a rock layer is
• How organisms in the past were related to each other
• The composition of a rock layer
• Which rock layers in different areas are the same age

A geologist hiking through the woods in Ohio finds rocks containing fossils in a stream bank. The fossils look similar to animals currently living in the ocean. Which conclusion should the geologist make based on the discovery of these fossils?

• Fossils washed upstream from the ocean
• Animals that live in the stream today lived in the ocean long ago.
• The area of the woods and stream was an ocean long ago.
• The area with the stream will become part of the ocean in the future.

What is 'half-life'?

• The age determined by the things around it.
• The age of an igneous rock.
• The age determined by radioactive dating.
• The time it takes for 1/2 of the radioactive atoms to decay in an element.

What is radio active decay?

• The preserved remains of an organism.
• Atoms in an unstable element break down to form another element.
• When things die and their remains are buried.
• The time it takes for 1/2 of the radioactive atoms to decay in an element.

Tags

NGSS.HS-PS1-8

What does radio active dating works best to determine?

• The age determined by the things around it.
• The age of an igneous rock.
• The age determined by radioactive dating.
• The time it takes for 1/2 of the radioactive atoms to decay in an element.

What type of fossil is this?

• Mold
• Cast
• Preserved remains
• Trace fossil

What type of fossil is this?

• Mold 
• Cast
• Preserved remains
• Petrified

What type of fossil is this?

• Mold
• Cast
• Carbon Film
• Trace fossil

What is hardened tree sap?

• coprolites
• index fossils
• gastroliths
• amber