Unit 2 Study Guide

What force holds stars together in a galaxy?

• Friction
• Nuclear force
• Electromagnetism
• Gravity

Tags

NGSS.HS-PS2-4

What two elements were formed shortly after the Big Bang?

• Nitrogen and Argon
• Oxygen and Carbon
• Lithium and Beryllium
• Hydrogen and Helium

Answer explanation

Hydrogen and Helium are the correct answers because they are the lightest elements on the periodic table.

Tags

NGSS.HS-ESS1-2

TRUE or FALSE: Our universe has not changed since it was formed

• TRUE
• FALSE

Answer explanation

The universe is constantly changing.

Tags

NGSS.HS-ESS1-2

How old is the universe?

• 10 billion years
• 4.5 billion years
• 20 billion years
• 13.8 billion years

Tags

NGSS.HS-ESS1-2

Why would images from a telescope IN SPACE be clearer than images from a telescope on EARTH’S SURFACE?

• Images from a telescope in space are clearer because they are not affected by Earth's atmosphere.
• Earth's atmosphere enhances the clarity of images from telescopes.
• Space telescopes are smaller and less powerful than ground telescopes.
• Images from a telescope on Earth are clearer due to better technology.

What is measured by a light year?

• Distance in space

• Brightness of stars

• Temperature of celestial bodies

• Time taken for light to travel

Answer explanation

A "light year" measures the distance that light travels in a year. It is a very large distance! So we use light years to measure large distances, to objects outside of our solar system.

What is the name of the first stage of a star's life cycle? Hint: it is made of dust and gas.

What determines the path a star takes in its life cycle?

• The color of the star.
• The distance from Earth.
• The temperature of the star's surface.
• The initial mass of the star.

Answer explanation

Stars with a larger mass follow a different path than stars with smaller masses. For example, a supergiant star will end as a black hole, whereas an average star (like our sun), will end as a dwarf star.

Tags

NGSS.HS-ESS1-1

What stage in a star's life cycle is the longest? Meaning, which stage does a star spend most of its life in?

• Main sequence
• Red giant
• White dwarf
• Neutron star

Tags

NGSS.HS-ESS1-3

How do we measure the brightness of a star as it appears from Earth?

• size and mass

• apparent magnitude

• color temperature

• absolute magnitude