Elevate Science: Unit 8 Review

Which term describes a gap in the geologic record that occurs when sedimentary rocks cover an eroded surface?

• extrusion

• fault

• intrusion

• unconformity

Which term describes the time it takes for half of a radioactive element's atoms to decay?

• absolute age

• half-life

• radioactive decay

• relative age

Tags

NGSS.HS-PS1-8

Which statement best desribes one rule for determining the relative age of a rock layer?

• A fault is always younger than the rock it cuts through.

• An extrusion is always older than the rocks below it.

• An index fossil is always younger than the rock layer it occurs in.

• An intrusion is always older than the rock layers around it.

Tags

NGSS.MS-ESS1-4

Which of the following conclusions can geologists draw about a limestone rock layer based on the law of superposition?

• The limestone layer is 2 million years old.

• The limestone layer contains 2 million fossils.

• The limestone layer is younger than the sandstone layer below it.

• The limestone layer is the same age as another layer 100 kilometers away.

Into which units is the geologic time scale subdivided?

• relative ages

• absolute ages

• months and days

• eras and periods

Tags

NGSS.MS-ESS1-4

What do geologists mostly study to develop the geologic time scale?

• Earth's rotation

• tectonic plate motions

• volcanoes and earthquakes

• rock layers and index fossils

Tags

NGSS.MS-ESS1-4

NGSS.MS-LS4-1

How do geologists use radioactive dating in developing the geologic time scale?

• to identify index fossils

• to identify types of rocks

• to place rocks in order by relative age

• to determine the absolute age of rocks

Tags

NGSS.MS-ESS1-4

Which event occurred in the Cenozoic era?

• first mammals

• spread of mammals

• first flowering plants

• spread of ferns and conifers

What were Earth's earliest multicellular organisms?

• bacteria

• land plants

• vertebrates

• invertebrates