What is the name of the process whereby a nucleus is split into smaller parts
Which particle must be absorbed 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 fusion?
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 is the role of the moderator in a fission reactor?
It 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 control rods which can be lowered into the reactor to absorb neutrons and so slow down the chain reaction
What does the atomic number of an atom represent?
The number of protons in the atom
Which radioactive particle is made of two neutrons and two protons (a helium nucleus)?
Which radioactive particle is an electron?
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.
Which type of radiation is not a particle?
(it is electromagnetic radiation)
Order the 3 types of radiation by decreasing ionising power
1) Alpha (most ionising),
3) gamma (least ionising)
Which type of radiation has a range of 2-3 cm in air?
Which type of radiation is stopped by thin aluminium?
What does the atomic number of an atom tell us?
How many protons it contains
What does the mass number of an element tell us?
The number of protons and neutrons in an element added together.
What is an ion?
An atom that has lost or gained electrons
In nuclear fission what is a chain reaction?
When the neutrons released from the splitting of one nucleus hit other nuclei and make them split and release more neutrons. (It goes on and on and on and on - just like the links in a chain)
In nuclear fission, what are daughter nuclei?
The smaller nuclei produced from the splitting of a larger nucleus
These are the steps in making electricity from a nuclear reactor. Put them into the right order:
a) The turbine turns the generator
b) Water is heated up
c) Nuclear reactor produces heat
d) Water turns to steam
e) The generator makes electricity
f) Steam turns the turbine
Nuclear reactor produces heat
Water is heated up
Water turns to steam
Steam turns the turbine
The turbine turns the generator
The generator makes electricity
What process in science do new ideas have to go through before they are accepted?
Evidence has to be produced
Experiments must be repeated
Evidence is peer reviewed (checked by other scientists)