What is the force which pulls the dust and gas together?
Gravitational
The smaller masses may be attracted by the star and become Planets
Our nearest star, the Sun, is stable because the gravitational forces and the radiation pressure are equal
Describe what happens to the nucleus of an atom during nuclear fission
It splits into smaller parts and neutrons are emitted
Nuclear fusion
the nuclei of two atoms joining together
Nuclear fission
the nucleus of an atom splitting into several pieces
Ionisation
an atom losing an electron
Electric current
an electric charge moving through a metal
Explain briefly how stars like the Sun are thought to have been formed.
-Dust and gas pulled together by gravity
-nuclear fusion starts
Describe the process of nuclear fusion.
Two nuclei join forming a larger nuclei
Where does nuclear fusion happen naturally?
Star
Explain briefly the difference between nuclear fission and nuclear fusion
fission is the splitting of a nucleus
fusion is the joining of nuclei
What is released during both nuclear fission and nuclear fusion?
Energy
Stars are stable during the ‘main sequence’ period of the life cycle. Why?
Forces are balanced
Describe what happens to a star much bigger than the Sun, once the star reaches the end of the ‘main sequence’ period of its life cycle.
Gravitational force balanced by radiation pressure
Describe what happens to a star much bigger than the Sun, once the star reaches the end of the ‘main sequence’ period of its life cycle.
star runs out of hydrogen and expands and cools forming a red super giant which explodes as a supernova becoming a neutron star
Shortly after the ‘big bang’, hydrogen was the only element in the Universe. Explain how the other elements came to be formed.
By fusion of hydrogen to helium and elements heavier than iron are only produced in a supernova
Explain why the Sun remains stable.
Gravity and radiation pressure in the correct direction of forces are balanced
What happens to the elements produced in a supernova?
Distributed throughout the Universe
Explain the difference between a protostar and a main sequence star.
A protostar is at a lower temperature as fusion hasn’t started
Energy is released from nuclear fuels by the process of nuclear fission. This energy is used to generate electricity. Describe how this energy is used to generate electricity
used to heat and water to produce steam which drives a turbine
Explain the advantages of using energy from nuclear fuels to generate electricity rather than using energy from the wind.
Concentrated source of energy that’s able to generate continuously the energy from fission is used to heat water to steam to turn a turbine linked to a generator
Describe how 'carbon capture' would prevent the build-up of carbon dioxide in the atmosphere.
carbon dioxide is not released but is stored
Explain how atoms of very heavy elements, such as gold (Au), were formed.
Fusion of other elements during a supernova
electrical forces inside a nucleus contribute to nuclear
instability
uranium-235, uranium-238 and uranium-239 are different
isotopes
nuclear fission occurs when
electrical forces inside a nucleus overpower nuclear forces
besides U-235, another material that undergoes fission readily is
plutonium-239
a benefit to using nuclear fission power is that it
supplies a lot of electricity, conserves organic fuels, like oil, coal and wood, eleiminates huge quantifies of sulfur oxides, which pollute our air
the release of energy in nuclear fission is consistent with the fact that uranium has
more mas per nucleon than either of the two fragments
a breeder reactor is more efficient than a convertional nuclear fission reactor in that
nuclear fuel is created inside the reactor, unfissionable material is converted into fissionable material, there is plentiful supply of material for itSee an expert-written answer!We have an expert-written solution to this problem!
in a breeder reactor
uranium is converted into plutonium
reactions that take place in a breeder reactor primarily change
elements into different elements
in gaseous form at the same temperature, the average speed of U-238 compared to the speed of U-235 is
less
compared to a neutron bouncing off a gold nucleus, a neutron bouncing off hydrogen nucleus has
less speed
a mass spectrograph separates ions by using
a magnetic field
a graph of nuclear mass per nucleon for all the elements