2nd Quarter assessment Practice age dating of rock

Rocks or fossils found in the LOWEST layers are ___________ than those in the top layers

• younger
• older
• the same age
• more common

what is the main compound used to determine absolute age of once living things less than 50,000 years old?

• carbon-14
• calcium-69
• lead-21
• organic material-9000

Knowing whether a rock is older or younger is known as

• Absolute age
• Relative age
• Radioactive decay
• Half-life

Some elements are radioactive which means ______________

• they are always the same and never change
• they give off energy as they break down

The RATE at which a radioactive element decays remains constant

• TRUE
• FALSE
• Cannot be calculated

Geologists use RADIOACTIVE DATING to determine the RELATIVE AGE of rocks.

• TRUE
• FALSE
• There is no way to know how old rocks are

The amount of time it takes for material that was radioactive to decay into a more stable form

• Absolute age
• Relative age
• Half-life

The layer labeled YOUNGEST is an example of

• a sedimentary rock layer
• an igneous intrusion
• a hardened lava flow
• an extrusion

Is the Hermit Shale OLDER or YOUNGER than the Coconino Sandstone?

• Older
• Younger
• 1 million years older

Relative Age

• The age of rock compared to the age of rock layers
• The amount of rock layers there are in one area
• How old rocks are in terms of superposition
• How old each rock layer is