Unit 1 Vocabulary Definitions

______ is a measure of how much "stuff" is packed into a certain space.

• mass

• density

• gravity

• inertia

______ is the force that attracts a body toward the center of any other physical body having mass

• mass

• density

• gravity

• inertia

______ the amount of matter an object has

• mass

• density

• gravity

• inertia

_____ is a huge ball of gas held together by gravity. Its central core is extremely hot and produces energy. Its size and mass cause planets and celestial bodies to orbit it.

• A star

• A solar system

• Big Bang Theory

_____ says the universe began with a tremendous explosion 13.7 billion years ago.

• A star

• Evolution Theory

• Big Bang Theory

The collection of eight planets and their moons in orbit around the sun, together with smaller bodies in the form of asteroids, meteoroids, and comets is called _______

• a universe

• A solar system

• Big Bang Theory

• a galaxy

All existing matter and space considered as a whole is called ______. Three different types of galaxies can be seen it it.

• the universe

• A solar system

• Big Bang Theory

• a galaxy

A collection of gas, dust, and a system of millions or billions of stars and their solar systems held together by gravitational attraction in called _______.

• the universe

• A solar system

• Big Bang Therory

• a galaxy

The name of our _____ is called the Milky Way.

• universe

• Asolar system

• Big Bang Theory

• galaxy

The force that attracts a body toward the center of any other physical body having mass. This force keeps the planets and the asteroid belt from escaping the solar system. What force is being described?

• Orbit

• Gravity

• Gravity