PS 10.2 Formative

The half-life of cobalt-60 is 5.3 years. What fraction of a sample remains after 21.2 years?

• one half

• one quarter

• one eighth

• one sixteenth

Tags

NGSS.HS-PS1-8

Which of the following is a radioisotope commonly used in dating archeological artifacts?

• nitrogen-14

• carbon-12

• carbon-14

• uranium-235

The time required for one half of a sample of a radioisotope to decay.

• half-life

• decay-life

• ionization rate

• carbon-14

Tags

NGSS.HS-PS1-8

A sample of Thorium in the lab is tested 72 days after it is brought in. The number of Thorium-234 atoms is one-eighth as much as it was before. What is the half life of Thorium-234?

• 24 days

• 48 days

• 72 days

• 9 days

Tags

NGSS.HS-PS1-8

What is the half-life of Carbon-14?

• 1620 years

• 5730 years

• 75,200 years

• 24 days

Tags

NGSS.HS-PS1-8

Nuclear decay rates are constant, regardless of temperature, pressure, or surface area.

• true

• false

Tags

NGSS.HS-PS1-8

If the ratio of carbon-14 to carbon-12 in a fossil is half the ratio in the atmosphere, then the organism lived how long ago?

• 5730 years

• 2865 years

• 11,460 years

• 50,000 years

Radiocarbon dating can be used to date any carbon-containing object, no matter how old it is.

• true

• false

Scientists use the half-lives of potassium-40, uranium-235, and uranium-238 to determine the age of ___

• rock formations

• once living things

• meteorites

• plant fossils

Tags

NGSS.HS-PS1-8

NGSS.HS-ESS1-5

When a plant or animal dies, it's carbon-14 levels _____

• increase

• decrease

• stay the same