WorksheetsStellar Evolution and Nuclear Fusion Assessment
Total questions: 20
Worksheet time: 10mins
Name
Class
Date
1.
According to the Hertzsprung-Russell diagram, where are hot, blue, bright stars typically located?
a)
Lower right corner
b)
Upper left corner
c)
Middle section
d)
Lower left corner
2.
What is the primary process that occurs in star cores, releasing enormous amounts of energy?
a)
Nuclear fission
b)
Nuclear fusion
c)
Radioactive decay
d)
Thermal radiation
3.
At what temperature does fusion begin in a forming star?
a)
15 million K
b)
5 million K
c)
10 million K
d)
20 million K
4.
What happens when a star's core hydrogen fuel is depleted?
a)
The star immediately explodes
b)
The star turns into a black hole
c)
The core expands and cools
d)
The core contracts and heats up
5.
What is the final fate of a massive star after a supernova explosion?
a)
White dwarf
b)
Red giant
c)
Neutron star or black hole
d)
Main sequence star
6.
What characterizes the main sequence stars on the H-R diagram?
a)
Random scatter pattern
b)
Vertical line pattern
c)
Horizontal line pattern
d)
Diagonal band pattern
7.
What happens to the outer layers of a giant star when helium is exhausted?
a)
They collapse inward
b)
They escape into space
c)
They freeze solid
d)
They become plasma
8.
What is the defining characteristic of a black hole's event horizon?
a)
It emits intense radiation
b)
Nothing can escape from within it
c)
It has a visible surface
d)
It produces new stars
9.
What percentage of stars do NOT fall in the main sequence?
a)
25%
b)
5%
c)
10%
d)
15%
10.
What element is formed in the core when helium nuclei fuse?
a)
Oxygen
b)
Carbon
c)
Nitrogen
d)
Neon
11.
What is the temperature in the Sun's core where nuclear fusion occurs?
a)
10 million K
b)
15 million K
c)
5 million K
d)
20 million K
12.
What happens to matter emitted by a star over its lifetime?
a)
It disappears completely
b)
It becomes dark matter
c)
It can become part of a new nebula
d)
It turns into asteroids
13.
What causes a nebula to contract and break apart?
a)
Solar winds
b)
Magnetic fields
c)
Gravitational instability
d)
Thermal pressure
14.
Where are cool, red, dim stars located on the H-R diagram?
a)
Upper right
b)
Lower left
c)
Lower right
d)
Middle section
15.
What forms when the core of a tremendously massive supernova collapses to a point?
a)
White dwarf
b)
Black hole
c)
Neutron star
d)
Red giant
16.
What is the stable phase in a star's life called?
a)
Giant phase
b)
Main sequence phase
c)
Nebula phase
d)
Supernova phase
17.
What happens when iron forms in a massive star's core?
a)
Fusion continues indefinitely
b)
The star becomes stable
c)
Fusion stops
d)
The star expands
18.
What maintains the balance in a main sequence star?
a)
Magnetic fields and radiation
b)
Fusion heat and gravity
c)
Solar winds and pressure
d)
Temperature and density
19.
What type of star forms when a giant star's core contracts into a hot, dense, small star?
a)
White dwarf
b)
Red giant
c)
Blue giant
d)
Yellow dwarf
20.
What is the primary fuel for nuclear fusion in a star's core?
a)
Helium
b)
Carbon
c)
Hydrogen
d)
Oxygen
100 %
