6.4 Galaxies Practice Test

The classification of Galaxy is based on its observable characteristics. Which of these characteristics is used to classify galaxies?

• A. shape
• B. temperature
• C. types of forces
• D. chemical elements

A galaxy has forces similar to the ones in the solar system. Which force holds this galaxy together?

• A. elastic force
• B. electric force
• C. magnetic force
• D. gravitational force

The Milky Way and other galaxies are made of similar elements. Which element is found in highest quantity in these galaxies?

• A. carbon
• B. nitrogen
• C. oxygen
• D. hydrogen

A _______________ is a group of millions or even billions of stars.

• A. galaxy
• B. constellation
• C. universe
• D. solar system

Look carefully at the graphic organizer below. In the universe which of these is biggest?

• A. a galaxy
• B. a planet
• C. a city
• D. a country

Which component (part) of the universe is shown in the picture?

• A. galaxy
• B. planet
• C. comet
• D. moon

___________ a specific point in space

• space
• position
• constellation
• hydrogen

___________ a system of objects that revolve around a star

• galaxy
• constellation
• universe
• solar system

___________________ everything that exists in, on and around the Earth.

• galaxy
• constellation
• universe
• solar system

________________ the distance light travels in a vacuum in one year; about 6 trillion miles

• space year
• light year
• light time
• vacuum year