Radiation
What is emitted from a nucleus during alpha decay?
2 protons and 2 neutrons (a helium atom!)
Which reaction produces nuclear waste that needs to be handled and disposed of properly?
Nuclear fission
Assuming you start with 100%, this is the percent of your radioactive sample that will be left after 2 half lives have passed.
25%
What is a half-life?
Time for half of a radioactive substance to decay
What is the charge of a beta particle?
-1
What particle is released during beta decay?
Electron
What type of nuclear reaction commonly involves hydrogen and helium atoms?
Fusion
This isotope has a well-known half life of 5,730 years and is most commonly used to date ancient fossils
Carbon-14
What is radioactivity?
Emission of radiation from unstable nuclei
Why are some isotopes radioactive?
They have an imbalance of protons and neutrons in the nucleus that makes it unstable
Which radiation type has the greatest penetration?
Gamma
What is an application of nuclear fission?
Generating energy in nuclear power plants
If a radioisotope has a half life of 200 years, how much of a 60 gram sample would be left after 600 years?
7.5 grams
What is an isotope?
An atom with the same number of protons but different neutrons
In an isotope symbol, what does the top number tell us, and what does the bottom number tell us? Which number do we use to figure out which element it is?
Top= mass # (p + n)
Bottom= atomic number (# p)
Atomic number tells us the atom identity
Write out the following nuclear equation: Radium-226 undergoes radioactive decay, producing Radon-222 and an alpha particle.
226/88 Ra --> 222/86 Rn + 4/2 He
Which nuclear process powers the sun?
Fusion
Sodium-24 has a half life of 20 hours. How much sodium-24 in a 500 gram sample will remain after 100 hours?
15.635 grams
What is a gamma ray?
A form of electromagnetic radiation/ energy that is emitted from a nucleus.
What is required for nuclear fusion to occur?
Extremely high temperatures and pressure
What element forms when uranium-238 emits an alpha particle?
Thorium-234
What is the difference between nuclear fission and nuclear fusion?
fission= splitting one large nucleus into two small
fusion= fusing two small nuclei into one larger one
A certain radioactive isotope has a half-life of 5 hours.
If you start with a 40-gram sample, how much will remain after 25 hours?
1.25 grams
What is nuclear fission?
The process of splitting a large nucleus like uranium into two smaller nuclei, releasing a ton of energy in the process.
What are the 2 requirements that must be met in order to estimate the age of an object using Carbon-14 and WHY?
Has to have once been alive and has to be less than 35,000 years old