Unit 10 Review

The earth is ______________of years old

• Hundreds

• Millions

• Billions

• Trillions

Mammals are a dominant group in which era?

• Cenozoic

• Mesozoic

• Paleozoic

• Cambrianozoic

How old do Paleontologists believe the Earth is?

• 2019 years old

• 3.6 billion years old

• 4.6 billion years old

• 4.6 million years old

What type of event usually marks the end of an Era

• A Mass Extinction

• A Quinceanera

• An earthquake

• A Volcanic Eruption

Which era is the most recent, the one that we are currently in?

• Mesozoic

• Paleozoic

• Cenozoic

• Precambrian

The dinosaurs and reptiles were dominant in which Era?

• Precambrian

• Mesozoic

• Paleozoic

• Cenozoic

The half-life of strontium-90 is 25 years. How much strontium-90 will remain after 100 years if the initial amount is 4.0 g?

• 3.0g
• 0.25mg
• 0.3g
• 0.25g

Tags

CCSS.HSF.LE.A.4

What is the half-life of iodine-131?

• 32 days
• 8 days
• 16 days
• 24 days

The % of the parent isotope remaining after 1 Half Life.

• 50%

• 25%

• 12.5%

• 6.25%

A sample will lose half of the parent isotope after 1 half life.

• TRUE

• FALSE