Before the Big Bang, the universe was filled with energy that was incredibly hot and ______.

• Light

• Dense

• Cold

• Dark

Fill in the blank: The temperature of the universe cooled enough to form nuclei after about ____ minutes.

• 1

• 3

• 5

• 10

What is the smallest and simplest element according to the vocabulary list?

• Helium

• Hydrogen

• Oxygen

• Carbon

Fill in the blank: Helium is described as the second ____ and simplest element.

• Largest

• Smallest

• Heaviest

• Most complex

What happened after 100 million years according to the Big Bang Theory?

• The Earth was formed

• Atoms of gas came together due to gravity

• The first humans appeared

• The universe stopped expanding.

How long after the Big Bang did the first stars form?

• 10 million years

• 50 million years

• 100 million years

• 200 million years

Fill in the blank: The second step in the 'Discover the Diagram' section is to ______ what you are learning.

• Read

• Explain

• Discover

Fill in the blank: The Big Bang theory explains the ____ of the universe.

• A) End

• B) Beginning

• C) Middle

• D) Expansion

Fill in the blank: The universe's average temperature ____ as it grew.

• Increased

• Decreased

• Remained constant

• Fluctuated

Fill in the blank: The Big Bang theory describes the formation of the first ____.

• A) Stars

• B) Atoms

• C) Galaxies

• D) Planets