8th Grade Science Prep Quiz 1 – Key Vocabulary

Vocabulary flashcards covering physics, chemistry, biology, Earth science, space science, and the scientific method from the 8th Grade Science Prep Quiz 1.

Newton's First Law of Motion

Principle stating that an object in motion stays in motion at constant speed and in a straight line unless acted upon by an external force.

Chemical Change

A process that produces new substances with properties different from the original; usually irreversible by physical means.

Rusting of Iron

A chemical change in which iron reacts with oxygen and moisture to form iron oxide (rust).

Mitochondria

Organelles in cells responsible for producing energy (ATP) through cellular respiration; known as the cell's "powerhouse."

Earth's Inner Core

The solid innermost layer of Earth composed mainly of iron and nickel.

Phases of the Moon

The changing appearances of the Moon caused by observing different portions of its sunlit half as it orbits Earth.

Independent Variable

The factor intentionally changed by a researcher in an experiment, such as the amount of sunlight given to plants.

Dependent Variable

The factor measured or observed in an experiment in response to changes in the independent variable, such as the height of the plants.