Analyzing evidence
What are the two elements that make up most of the Sun?
Hydrogen and helium.
What does the Big Bang Theory describe?
The universe began in a very hot, very dense state and has been expanding.
What did Edwin Hubble discover about galaxies?
He found evidence that galaxies are moving away from each other/the universe is expanding.
What is the Sun mostly made of?
Hydrogen and helium.
What is a chemical reaction?
A reaction in which atoms are rearranged to form new substances.
Which element makes up the largest percentage of the Sun?
Hydrogen
Who is credited with first proposing the idea of an expanding universe that became the basis for the Big Bang Theory?
Georges Lemaître
What does a redshift indicate?
An object is moving away from us.
What process produces the Sun's energy?
Nuclear fusion.
What is a nuclear reaction?
A reaction that changes the nucleus of an atom
What type of evidence could you use to determine what the Sun is made of?
Spectroscopy/data from the Sun's light
What does the Big Bang Theory suggest about the universe today?
The universe is still expanding.
What does a blueshift indicate?
An object is moving toward us
What happens during nuclear fusion in the Sun?
Hydrogen nuclei combine to form helium and release energy.
In a chemical reaction, what part of the atom is mainly involved?
The electrons/electron arrangement.
According to the Sun's energy diagram, what is the source of the Sun's energy?
Nuclear fusion.
Name two pieces of evidence that support the Big Bang Theory.
Galaxy redshift/expansion and cosmic microwave background radiation.
What is spectroscopy?
The study of the light/spectrum produced or absorbed by matter.
Why does the Sun have so much energy?
It contains enormous amounts of hydrogen and its intense temperature and pressure allow nuclear fusion to occur continuously.
In a nuclear reaction, what part of the atom changes?
The nucleus.
Use evidence to explain why scientists conclude that the Sun's energy comes from nuclear fusion.
The Sun contains abundant hydrogen, and the diagram shows hydrogen nuclei combining to form helium and release energy.
Why is cosmic microwave background radiation evidence for the Big Bang?
It is leftover radiation from the early, hot universe and is observed throughout space.
How can astronomers use spectroscopy to learn about stars?
They can analyze the wavelengths of light to determine information such as a star's chemical composition, temperature, and motion.
Explain how nuclear fusion produces energy in the Sun.
Hydrogen nuclei combine to form helium. A small amount of mass is converted into energy, releasing a tremendous amount of energy.
What is one major difference between chemical and nuclear reactions?
Nuclear reactions involve changes to the nucleus and can release much more energy than chemical reactions.