Download Fill in the blanks of each frame using the list of missing words given

Instructions
Fill in the blanks of each frame using the list of
missing words given. Cut out each frame and arrange
them on your page in order, then stick them down.
The first two frames are already in the right order.
Gas and dust, mainly made up
of ___________ atoms with
some helium atoms, are
dispersed thinly throughout
space.
When the temperature
is high enough, the
cloud glows dimly,
forming a
________________.
Missing words:
mass
gravitationally
hydrogen
Brown Dwarf
PE
hydrogen burning
KE
temperature
nuclear fusion
If the mass is high enough, in the centre of
the cloud, hydrogen atoms are stripped of
their ____________. The nuclei have
enough energy to overcome their
__________________________ and fuse
together.
The fusing of two atoms is called
__________________. Sometimes this
is called ___________________, but
it isn’t burning as we know it.
A large, spherical
cloud forms. The ___
decreases, and the
___ and __________
increase.
electrostatic repulsion
protostar
electrons
Each atom is _____________
attracted to each other, and so
is pulled together, creating a
dense region, which attracts
more and more atoms.
If the cloud doesn’t have enough
_______, it remains in this way
for the rest of its life, and is
called a __________________.
Instructions
Answer the questions or follow the instructions in each frame in the spaces provided.
1. What is nuclear fusion?
_________________________
_________________________
_________________________
_________________________
_________________________
___
2. Write down the 3 nuclear equations described in the previous frame
in the space below.
2 hydrogen
nuclei/protons join
together to form a
deuterium nucleus, a
positron, and a neutrino.
The deuterium
nucleus fuses
with another
proton to form a
helium-3 nucleus.
Two of these
helium-3 nuclei fuse
to form a helium-4
nucleus, and two
more protons.
3. What happens to the mass difference
between the initial 4 protons and the helium
atom created?
_________________________________
_________________________________
4. Up to which element can nuclear
fusion occur? Elements heavier than
this undergo nuclear fission instead.
What happens in nuclear fission?
_________________________________________
_________________________________________
_________________________________________
_________________________________________
______
_________________________________
_________________________________
_________________________________
Instructions: Fill in the gaps with the words in the bottom right corner (words may be used more than once). Also, illustrate the
descriptions in each frame.
Once _________ starts,
the star is no longer
known as a protostar, but
is called a __________
__________________.
A ________________
star is a low-mass, dim
main sequence star. It
transports energy from
its core to the surface
by __________ alone.
A medium sized main sequence star transports energy via
______________, through the ___________________.
The energy is transported further through the
_____________________ by _______________, to the
surface. When the energy reaches the surface, which is
called the ________________, it is radiated out into
space.
Missing Words kinetic
sizes
The energy that travels from the core to the star’s
main sequence star
radiation pressure
surface gives surrounding atoms more ___________
energy. The atoms start moving away from the star’s
Red Dwarf
centre, causing the star to expand, and creating an
radiative zone
outward ________________________. This acts
against the pull of the ____________, and for most
of the star’s life, the two are balanced.
Stars will have collected different amounts of gas, so
are different ________. What happens next depends
photosphere
on the initial size of the star at the start of its life.
convection zone
fusion
convection
gravity
radiation
Instructions: In this exercise, you will describe the death of a low-mass star in your own words. The pictures are arranged in order
and are there to guide you. Cut them out and stick them on your page, and write a description to go with each image. Make sure you
answer every question with each image in your descriptions.
1. What is the
maximum size of a
low-mass star?
2. What happens to the amount of hydrogen and
helium in the core of a main sequence star towards
the end of its life?
3. What happens to fusion?
1. What happens to the outer
layers and the core?
2. When the temperature gets
high enough, what happens to the
helium in the core?
1. What
happens to the
fusion
process, and
why?
2. What then
happens to the
core?
1. What happens to the
balance between the
outward radiation
pressure and the
gravitational inward pull?
2. What happens to the
radius of the star?
1. What happens to
the outer layers of
the star?
2. What happens
to the total mass?
1. As the star collapses,
what happens to the
pressure and temperature
of the core?
2. The star then expands
again. What causes this
expansion?
1. The star then cools
and shrinks. What
causes the star to stop
shrinking?
2. What is the star now
called?
1. What happens next to the
size of the star?
2. What type of star does it
become?
1. What happens to the
remaining heat of the star?
2. Once the heat has all gone,
what happens to the star?
Instructions
The diagrams are in the right order, but the descriptions to go with each one aren’t. Cut out each diagram and caption, and match the
correct description to each diagram, and finish off each description.
When the star runs out of the element it
A black hole is formed instead of a neutron
All of the naturally occurring elements in
is fusing in the core, the core contracts.
star if the star was approximately 15 times
the Universe are created by just nuclear
This raises the temperature and
more massive than the Sun. The collapse of
fusion. Elements above iron are created
pressure sufficiently such that
the star would be so great that not even
when __________________________
______________________________
neutrons can withstand the high pressures.
______________________________
______________________________
The core collapses into a singularity and is so
______________________________
______________________________.
dense that not even light can ___________
______________________________
When the core is mostly made up of iron
_________________________________.
______________________________
nuclei (which cannot fuse together),
nuclear fusion finally stops and the star
The collapse of the star recoils and bounces
begins to collapse for the last time.
back outwards because the iron nuclei
The collapse of the star recoils and
_________________________________
bounces back outwards because the iron
nuclei ________________________
______________________________
______________________________
______________________________
The core contracts due to gravity,
growing hotter and denser so that
heavier nuclei can begin to fuse. This
temporarily stops any further collapse
because ________________________
______________________________
______________________________
_____________________
For a larger mass star, instead of
_________________________________
_________________________________
_______________________________
The remaining core left over from the
______________________________
________________
The shockwave sweeps material out from
the star, and the material is flown out
into the Universe in a huge explosion
called a ________________________.
A neutron star is made up entirely of
supernova can form _______________
neutrons, which are created because
______________________________
______________________________
______________________________
______________________________
______________________________
Pulsars are ______________________
______________________________
______________________________.
______________________________
We can observe the pulses of radiation
when __________________________
______________________________
______________________________
__
Neutron stars spin very rapidly, turning
one revolution in seconds. They can have
swelling into a Red Giant, it swells
enormous _______________________
into a ______________________
______________________________
______________________________
A star with a high mass remains as a
main sequence star for a shorter amount
of time than a low mass star. This is
because ________________________
______________________________
______________________________
______________________________
______________________________
______________________________
________________
Answers
The Birth of a Star
Gas and dust, mainly made up
of hydrogen atoms with
some helium atoms, are
dispersed thinly throughout
space.
Each atom is gravitationally
attracted to each other, and so
is pulled together, creating a
dense region, which attracts
more and more atoms.
If the cloud doesn’t have enough
mass, it remains in this way for
the rest of its life, and is called a
Brown Dwarf.
A large, spherical
cloud forms. The GPE
decreases, and the KE
and temperature
increase.
If the mass is high enough, in the centre of the cloud,
hydrogen atoms are stripped of their electrons. The
nuclei have enough energy to overcome their
electrostatic repulsion and fuse together.
When the temperature
is high enough, the
cloud glows dimly,
forming a protostar.
The fusing of two atoms is called
nuclear fusion. Sometimes this is called
hydrogen burning, but it isn’t burning as
we know it.
Nuclear Fusion
1. Nuclear fusion is a process where lighter nuclei join together to form a heavier nuclei, e.g. 4 hydrogen nuclei become one helium nucleus.
2.
3. The mass difference is converted into energy and released.
4. Elements up to Iron can undergo nuclear fusion. In nuclear fission, heavier nuclei split into lighter nuclei.
Main Sequence Star
A medium sized main sequence star transports energy via radiation,
through the radiative zone. The energy is transported further
through the convection zone by convection, to the surface. When
the energy reaches the surface, which is called the photosphere, it is
radiated out into space.
Once fusion starts, the star is
no longer known as a
protostar, but is called a
main sequence star.
A Red Dwarf star is a lowmass, dim main sequence
star. It transports energy
from its core to the surface
by convection alone.
The energy that travels from the core to the
star’s surface gives surrounding atoms
more kinetic energy. The atoms start
moving away from the star’s centre,
causing the star to expand, and creating an
outward radiation pressure. This acts
against the pull of the gravity, and for most
of the star’s life, the two are balanced.
Stars will have collected
different amounts of gas, so
are different sizes. What
happens next depends on the
initial size of the star at the
start of its life.
Death of a Low Mass Star
If the star is less than 4 times
the mass of the Sun, it is a lowmass, or small star. Towards
the end of the star’s life, it
begins to run out of hydrogen
fuel to fuse together, and the
core is mostly made of helium.
Nuclear fusion in the core
therefore temporarily stops.
There is no longer anything
generating an outward pressure
to counteract the gravitational
inward pull. This makes the
outer layers of the star begin to
collapse inwards again.
No further fusion
takes place, as there is
not enough mass to
compress the carbon
further to fuse
together. The core
remains stabilised.
While the outer layers of the Red Giant continue to
expand, the core is still contracting so the
temperature continues to increase. The
temperature gets high enough for helium to start
fusing together, forming a heavier element, carbon.
As before, this makes the
temperature and pressure
increase. The temporary heat
creates outward pressure again
and counteracts the inward
force of gravity, pushing the
outer layers of the star
outwards.
Large amounts of matter
are ejected from the outer
layers of the Red Giant,
until only about 20% of the
star’s initial mass remains.
The star ends up expanding much more than it
did before, and it becomes about a hundred
times bigger than it’s ever been in its life. It has
turned into a Red Giant.
The star then begins to cool and shrinks until the
gravitational pull is balanced by the repulsion of the
electrons at the core. It stops shrinking and becomes
a White Dwarf, which is about half as massive as the
Sun, but only slightly bigger than the Earth.
As it can’t produce any more heat, it radiates away
the remaining heat for billions of years. Once the
heat has all gone, it sits as a cold dark mass, called
a Black Dwarf.
Death of a High Mass Star
A star with a high mass remains as a main sequence star for a
shorter amount of time than a low mass star.
This is because they are more massive, so the temperatures
and pressures are far greater, and the fuel gets used up much
more quickly, even though there is more of it.
The core contracts due to gravity, growing
hotter and denser so that heavier nuclei can
begin to fuse. This temporarily stops any further
collapse because an outward pressure is
produced when nuclear fusion takes place.
For a larger mass star, instead of swelling into a Red
Giant, it swells into a Red Supergiant – just a larger
version of a Red Giant.
The collapse of the star
recoils and bounces back
outwards because the iron
nuclei get crushed
together but the
electrostatic repulsive
force between them
overcome the
gravitational force.
When the star runs out of the element it is fusing in
the core, the core contracts. This raises the
temperature and pressure sufficiently such that
heavier elements begin to fuse. This happens for
heavier and heavier elements. When the core is
mostly made up of iron nuclei (which cannot fuse
together), nuclear fusion finally stops and the star
begins to collapse for the last time.
All of the naturally occurring elements in the Universe
are created by just nuclear fusion. Elements above
iron are created when an explosive shockwave is
created. The shockwave travels through the star’s
outer layers, heating the material it encounters to a
high enough temperature that they begin to fuse to
form new elements.
The shockwave sweeps material out
from the star, and the material is flown
out into the Universe in a huge explosion
called a supernova.
The remaining core left
over from the supernova
can either form a neutron
star, or if it’s massive
enough, can form a black
hole.
A neutron star is made up
entirely of neutrons,
which are created
because of the extremely
high pressure of the
remaining core. Electrons
are forced to combine
with protons, forming the
neutrons.
Neutron stars spin very
rapidly, turning one
revolution in seconds, and
can have enormous electric
and magnetic fields.
A black hole is formed instead of a neutron star if the star was approximately 15
times more massive than the Sun. The collapse of the star would be so great that not
even neutrons can withstand the high pressures. The core collapses into a
singularity and is so dense that not even light can escape its gravitational pull.
Pulsars are neutron stars that
pulse with electromagnetic
radiation.We can observe the
pulses of radiation when the
magnetic pole crosses our line of
sight.