Misc
The number of neutrons is equal to what?
Mass Number - Atomic Number
What type of radioactive decay doesn't affect mass or atomic number?
Gamma decay
What is a "half life"?
The time it takes for half of a substance to have undergone decay
What is c in the e=mc2
c = speed of light
Where does nuclear fusion occur naturally?
In the cores of stars
How many neutrons does U-235 have?
143
Which type of radioactive decay splits out helium?
Alpha decay
Why is it important to understand half lives with regards to nuclear energy production?
To know how long the waste needs to be stored before it can be "safe"
Explain the process of nuclear fission?
A neutron is shot into an unstable nuclei, causing it to split apart and release more neutrons
What is the definition of nuclear fusion?
Is a nuclear reaction in which the number of two atoms fuse together to form a larger nucleus.
What is transmutation?
When an atom gains or loses protons, turning it into a different element
A uranium atom undergoes alpha decay. What is the atomic number of the resulting nuclei?
23592U
90 (Thorium)
The half-life for Carbon-14 is 5,730 years. How long would it take for 25% of a sample of carbon to decay?
2,865 years
What are some of the downsides to nuclear fission energy?
It produces radioactive waste which can be very harmful to health, radioactive meltdowns, etc.
Nuclear fusion produces all the elements on the periodic table up to what?
Iron, 26
A Carbon atom undergoes Beta - decay. What is the resulting element?
Nitrogen
What happens when a nucleus becomes unstable?
It breaks apart
A substance that undergoes radioactive decay has 75% of its atoms decayed in 10,740 years. What is the half-life of this element?
5,370 years
What are some of the pros of nuclear energy?
It produces a lot of energy from not much fuel (very efficient), it produces much less waste than coal and no greenhouse gases ("clean")
How are the rest of the elements on the periodic table produced?
Supernova (star death)
Why does fusion require high temperature and pressures?
Because all nuclei are positively charged, so they repel each other. To fuse, those forces of repulsion have to be overcome with high temperature and pressure
How many ways can atoms decay? List them
Alpha, Beta - , Beta +, Gamma
Solve the following: A substance has an original mass of 100mg, with a half-life of 2 years.
After 10 years, how much of the substance has NOT decayed?
3.125mg
What does "e=mc2" mean in terms of nuclear energy?
It means matter can be transformed into energy
Why don't we use nuclear fusion for energy production?
It's very expensive and takes more energy to create the reaction than we can get from the reaction