Unit 2 Earth Science

Front

Define oceanic crust

Back

Made of basalt, thinner, but more dense.

Front

What is the process of radioactive decay?

Back

The process by which an unstable atomic nucleus loses energy by radiation.

Front

What is a half-life?

Back

The time required for half of the radioactive atoms in a sample to decay.

Front

Define asthenosphere

Back

Semi-fluid layer of the Earth's mantle beneath the lithosphere and above the mesosphere.

Front

What are independent variables in an experiment?

Back

Variables that the scientist changes or controls.

Front

What is continental drift?

Back

The theory that continents move across the Earth's surface over geological time.

Front

What is plate tectonics?

Back

The theory explaining the movement of the Earth's plates and the associated geological phenomena.

Front

What is the lithosphere?

Back

The rigid outer layer of the Earth, consisting of the crust and upper mantle.

Front

What is seafloor spreading?

Back

The process by which new oceanic crust is formed at mid-ocean ridges and older crust is pushed away.

Front

What is radiometric dating?

Back

A method used to date materials by comparing the abundance of a radioactive isotope to its decay products.