Geologic time , dating TEST

What is the purpose of determining the absolute age of a rock formation?

• To find out the color of the rock

• To determine the numeric age of the rock

• To measure the height of the rock

• To calculate the weight of the rock

Tags

NGSS.MS-ESS1-4

Why is determining absolute age using the rate of erosion practical only for features formed within the past 10,000 to 20,000 years?

• Erosion rates are constant over millions of years

• Erosion rates vary greatly over millions of years

• Erosion does not affect older features

• Erosion is faster in older features

What is one method geologists use to estimate the absolute age of sedimentary rocks?

• Measuring the color of the sediment

• Calculating the rate of sediment deposition

• Counting the number of fossils

• Analyzing the chemical composition

What are varves?

• Layers of volcanic ash

• Annual layers of sedimentary deposits

• Fossilized remains of plants

• Layers of igneous rock

Tags

NGSS.MS-ESS1-4

How are varves similar to tree rings?

• Both are used to estimate the age of an object

• Both are made of wood

• Both are found in tropical regions

• Both are used to measure temperature

What type of environment do varves generally form in?

• Deserts

• Glacial lakes

• Tropical forests

• Ocean floors

What is radiometric dating used for?

• To measure the absolute age of rocks

• To determine the color of rocks

• To find the weight of rocks

• To identify the texture of rocks

What is a half-life in the context of radioactive decay?

• The time it takes for all of a radioactive isotope to decay

• The time it takes for half of a radioactive isotope to decay

• The time it takes for a radioactive isotope to stop decaying

• The time it takes for a radioactive isotope to double in amount

Tags

NGSS.HS-PS1-8

If you start with 10 grams of a radioactive parent isotope, how much would remain after one half-life?

• 10 grams

• 7.5 grams

• 5 grams

• 2.5 grams

What happens to the remaining sample after two half-lives?

• One-fourth of the original isotope remains

• One-half of the original isotope remains

• Three-fourths of the original isotope remains

• The entire original isotope remains

Tags

NGSS.HS-PS1-8