Atomic Structure
The particles that determine an atom's mass.
protons + neutrons
What is half-life?
The time it takes for half of the the material/nuclei to decay.
This type of reaction occurs when a heavy atom splits.
Fission
The name of an atom with 4 protons and 5 neutrons
Beryllium
The joining of two (or more) lighter atoms into one larger atom.
Fusion
The atomic number is always the same as the number of this subatomic particle.
protons
A scientist is studying a new radioactive substance. The substance has a half-life of 5 years. Initially, the scientist has a sample weighing 160 grams.
How much of the substance will remain after 5 years?
80g
This type of reaction occurs in the Sun and other stars.
Fusion.
Atomic number of 6
Carbon
The charge of an ion with 8 protons and 10 electrons.
-2
The mass of an atom with 12 protons, 12 neutrons, and 10 electrons.
24 (atomic mass unit or amu)
A scientist starts with 80g of a radioactive material with a half-life of 4 hours. How much will remain after 12 hours?
10g
What element will be produced when two helium nuclei undergo fusion?
Beryllium
The name of an atom with 12 protons, 13 neutrons, and 10 electrons.
Magnesium
What fuel is used for nuclear fusion?
Hydrogen
This particular set of electrons are located in the outermost energy level of an atom and play a huge role in bonding.
valence electrons
If a substance has a half-life of 10 years, how much of a 100g sample will remain after 30 years?
12.5g
Uranium can be used as a fuel source for fission. Describe what happens to the uranium nucleus (be sure to include neutron in your explanation). Use both words & a diagram.
A neutron is fired at a Uranium-235 atom and splits the atom into two smaller atoms (barium & krypton) and multiple (3) neutrons are released --> chain reaction because those neutrons hit other nuclei and continue the fission process.
See image.
This noble gas does not have 8 valence electrons.
Helium
What is one of the two main requirements for fusion to occur?
1. extremely high temperature (millions of degrees)
2. a lot of pressure
What is the maximum number of electrons that can be found in the first energy level of an atom?
2
400
Archaeologists use the radioactive decay of carbon-14 to estimate the age of fossils and can be used on samples of bone, cloth, wood and plant fibers. The half-life of carbon-14 is 5,730 years. Several human bones have been unearthed at an archaeological dig. 25% of the original carbon-14 isotope is remaining and scientists estimate the bones to be ___________ years old.
11460 years
Name 1 benefit and 1 con/disadvantage to using nuclear fission for energy.
Benefits: a lot of energy is produced, less pollution than fossil fuels, require very small amount of starting reactant
Cons/Disadvantages: chain reaction can lead to nuclear meltdown if not properly cooled, nuclear waste produced
The mass of an isotope of Hydrogen with 2 neutrons.
3 amu (atomic mass unit)
Which process would be better for long-term energy production (fusion or fission)? Be sure to explain your answer using 2 or more pieces of evidence.
Fusion = cleaner (NO pollution & no waste), no radiation, plenty of fuel source (hydrogen), produces more energy than fission.