Universe Test Quizlet
According to the Big Bang theory, the universe began about
13.7 billion years ago
According to the diagram, the Sun has an absolute magnitude of
5
The Sun can continue to exist in its present state for another
5.5 billion years
If the atomic number of an element is 6 and its mass number is 14, how many neutrons are contained in the nucleus?
8
A star is said to be born when
A protostar reaches a temperature high enough for nuclear fusion to begin
The smallest particle of an element that still retains all the element's properties is an
Atom
According to the _____ theory, the universe formed in an instant, billions of years ago, in an enormous explosion.
Big Bang
What is the color of the hottest star?
Blue
In the cores of extremely hot red giants, nuclear reactions convert helium to
Carbon
Which of the following supports the Big Bang theory?
Cosmic background radiation
H-R diagrams are useful because they show a unique pattern that can be used to classify stars.
Fact
The beginning expansion of the Big Bang happened relatively slowly compared to how it is expanding now.
False
The farther away a galaxy is from us, the ____ it is moving away from us.
Faster
Which force is most responsible for the formation of a star?
Gravity
Which of the following is NOT a form of electromagnetic radiation?
Gravity
Most stars are made up of 98%
Hydrogen and helium
The Sun is a
Main-sequence star
The main factor that affects the evolution of a star is its
Mass
Another name for the interstellar matter that will eventually form a star is
Nebula
The remnant of a supernova is a
Neutron star
The source of the Sun's energy is
Nuclear fusion
The central region of an atom is called the
Nucleus
What is the atomic number of an element?
Number of protons
Which would be the name for a star embryo?
Protostar
Stars of what color have the coolest surface temperature?
Red
What is the next stage in the Sun's life cycle?
Red Giantt
Which of the stars has the lowest surface temperature?
Red Gianttt
When a main-sequence star has exhausted the fuel in its core, it becomes a
Red giant
Which of the following indicates that the universe is expanding?
Red shift of distant galaxies
All stars, regardless of size, eventually
Run out of fuel and collapse
By method of _____ we can know how much of each element is in a star because of the creation of absorption lines.
Spectroscopy
Which of the following is NOT a main part of the star life cycle?
Star twinkle
Massive stars terminate in a brilliant explosion called a
Supernova
A Hertzsprung-Russell (H-R0 diagram shows the relationship between
Temperature and absolute magnitude
As a star goes through this cycle their ____ changes.
Temperature, brightness, and luminosity
According to the diagram, which main-sequence stars are the brightest
The hottest
The Big Bang is responsible for the formation of two elements found in our universe, hydrogen, and helium.
True
Which of these stars is the oldest?
White dwarf
Carbon-12 has 6 neutrons, Carbon-14 has 8 neutrons. This makes Carbon-14 an
isotope
The mass number of an atom is obtained by totaling the number of
protons and neutrons