Name two substances that are commonly used as fuel in
What is the name of the process whereby a nucleus is split into smaller parts
Which particle must be
by uranium-235 or plutonium-239 for fission to occur?
What is produced when an unstable nucleus splits into two smaller nuclei?
Energy, and 2 or 3 neutrons
What is nuclear
The joining of two atomic nuclei to form a larger one
What is the name of the process by which energy is released in stars?
What force pulls together dust and gas within nebulae?
What is the name given to the stable part of a star's lifecycle?
What determines the lifecycle path of a star?
Where are elements
the mass of iron formed?
By a star in its stable period
the naturally occurring elements produced?
By fusion processes (either during a stars main sequence or during a supernova at the end of its life)
What name is given to a star
it starts its main sequence?
What is left at the end of the
What does a star the same size as the Sun become
its main sequence?
Put these into the correct sequence for a star like our sun:
Nebula => protostar => main sequence =>
red giant => white dwarf => black dwarf
What is a
An explosion at the end of the life of a
What is the role of the
in a fission reactor?
slows down the neutrons
so that they are slow enough to be absorbed by nuclei (and so continue the chain reaction)
How is a nuclear fission reactor controlled?
By the use of
s which can be inserted to absorb neutrons and so slow down the chain reaction
Why is nuclear fusion hard to achieve?
The positively charged nuclei will repel each each other and overcoming this requires a large amount of energy.
How are planets formed?
Matter from a protostar may not all become part of the star. The remainder will eventually be drawn together by gravity to form planets, moons, asteroids and comets.
The most common fuel in the sun is Hydrogen. Which two
of hydrogen fuse to form Helium?
AQA Physics 2.6 Fission and Fusion