SIA test UPDATED Exam Questions and
CORRECT Answers
Constellations - CORRECT ANSWER - A group of stars clustered together that forms a
pattern or shape
Magnitude - CORRECT ANSWER - A star's brightness
Describe the levels of magnitude - CORRECT ANSWER - The lower the number of the star
on the magnitude scale, the brighter it is
Sirius - CORRECT ANSWER - The brightest star in the universe
What does the color of a star indicate? - CORRECT ANSWER - Its surface temperature
What color are the hottest stars? - CORRECT ANSWER - Blue stars
What color are the coolest stars? - CORRECT ANSWER - Red stars
What color is the sun? - CORRECT ANSWER - White
Nuclear fusion - CORRECT ANSWER - The process by which the nuclear reactions inside a
star convert hydrogen into helium
Describe what gives a star its energy - CORRECT ANSWER - Stars produce energy through
nuclear fusion. This is a chemical reaction that occurs in the core of a star and converts hydrogen
to helium
, How many protons and neutrons does a standard hydrogen atom have in its nucleus? -
CORRECT ANSWER - 1 proton and no neutrons
Give the equation for the process by which stars fuse to hydrogen deuterium and hydrogen
tritium to form helium. - CORRECT ANSWER - D + T →He + n
Nebula - CORRECT ANSWER - A large cloud of dust and gas in space. This is what stars
begin their lives as
Protostar - CORRECT ANSWER - An early stage star or one that is just starting to develop.
This forms as gravity pulls gasses together into a ball
When does nuclear fusion begin? - CORRECT ANSWER - Once the temperature of a star
reaches 15,000,000 degrees Celsius
What does the lifespan of a star depend on and why? - CORRECT ANSWER - The lifespan of
a star depends on its mass because the more mass it has, the shorter its life span will be because
it will burn up all of its fuel faster
Very large, massive stars burn their fuel much ___________ than smaller stars - CORRECT
ANSWER - faster
The life span of smaller stars are much __________ than that of large, massive stars -
CORRECT ANSWER - longer
Main sequence - CORRECT ANSWER - Stars that fuse hydrogen to form helium in their
cores. Hot stars are brighter (top left), cool stars are dimmer (bottom right). Our sun is a main
sequence star.
What will decide the amount of time a star spends in the main sequence phase? - CORRECT
ANSWER - Its mass
CORRECT Answers
Constellations - CORRECT ANSWER - A group of stars clustered together that forms a
pattern or shape
Magnitude - CORRECT ANSWER - A star's brightness
Describe the levels of magnitude - CORRECT ANSWER - The lower the number of the star
on the magnitude scale, the brighter it is
Sirius - CORRECT ANSWER - The brightest star in the universe
What does the color of a star indicate? - CORRECT ANSWER - Its surface temperature
What color are the hottest stars? - CORRECT ANSWER - Blue stars
What color are the coolest stars? - CORRECT ANSWER - Red stars
What color is the sun? - CORRECT ANSWER - White
Nuclear fusion - CORRECT ANSWER - The process by which the nuclear reactions inside a
star convert hydrogen into helium
Describe what gives a star its energy - CORRECT ANSWER - Stars produce energy through
nuclear fusion. This is a chemical reaction that occurs in the core of a star and converts hydrogen
to helium
, How many protons and neutrons does a standard hydrogen atom have in its nucleus? -
CORRECT ANSWER - 1 proton and no neutrons
Give the equation for the process by which stars fuse to hydrogen deuterium and hydrogen
tritium to form helium. - CORRECT ANSWER - D + T →He + n
Nebula - CORRECT ANSWER - A large cloud of dust and gas in space. This is what stars
begin their lives as
Protostar - CORRECT ANSWER - An early stage star or one that is just starting to develop.
This forms as gravity pulls gasses together into a ball
When does nuclear fusion begin? - CORRECT ANSWER - Once the temperature of a star
reaches 15,000,000 degrees Celsius
What does the lifespan of a star depend on and why? - CORRECT ANSWER - The lifespan of
a star depends on its mass because the more mass it has, the shorter its life span will be because
it will burn up all of its fuel faster
Very large, massive stars burn their fuel much ___________ than smaller stars - CORRECT
ANSWER - faster
The life span of smaller stars are much __________ than that of large, massive stars -
CORRECT ANSWER - longer
Main sequence - CORRECT ANSWER - Stars that fuse hydrogen to form helium in their
cores. Hot stars are brighter (top left), cool stars are dimmer (bottom right). Our sun is a main
sequence star.
What will decide the amount of time a star spends in the main sequence phase? - CORRECT
ANSWER - Its mass
