Isotopes & Symbols
Isotopes of the same element have a different number of __________ in their atoms.
Neutrons
If a given isotope is very unstable, is it likely to have a SHORT half-life or a LONG half-life?
SHORT
Which type of radioactive decay can be stopped by a thin sheet of paper?
Alpha decay
Which process releases more energy for the same amount of fuel?
Fusion
What is the name of the multi-step fusion process within the sun?
Proton-proton chain
How many neutrons are in the nucleus of a F-19 atom?
10 neutrons
Name the radioisotope that is used for radiometric dating.
Carbon-14
What is the name of the particle emitted by beta-positive decay?
Positron
Name the particle that is fired at a large atom to start a chain reaction.
Neutron
If we could convert the mass of a pigeon (around 300 grams, or 0.3 kg) into pure energy, how much energy in Joules would that be?
2.7x1016 Joules
20 p, 22 n, 20 e
Cesium-137 has a half life of 30 years. If you had an 80 gram sample of Cs-137, how much of the radioactive material would be left after 90 years?
10 grams
Fill in the blank for the following beta decay equation. [Show picture]
6428Ni
Fill in the blanks: The sun is powered by the ________ (fission or fusion) of the element _________ to __________.
Fusion
Hydrogen to helium
What is the fancy name of the isotope H-2?
Deuterium
Write the nuclear symbol for a nucleus with 35 protons and 45 neutrons.
Top number: 80
Bottom number: 35
Element symbol: Br
Ms S orders a 100 gram sample of radium from Amazon. However, when the sample arrives exactly 2 weeks later, there are only 6.25 grams of radium, and the rest has decayed into other elements. What is the half-life of this radium?
3.5 days
Write the full equation for the alpha decay of U-238.
92U-238 --> 90Th-234 + 2He-4
a. What do we call the mass that goes "missing" after nuclear fission or fusion?
b. Where did this mass go?
Mass defect, gets converted to energy
Every second, the process of fusion in the sun releases 3.87x1026 Joules of energy. Using this information, how many kilograms of mass does the sun lose every second?
4.3x109 kg, or 4.3 billion kg
Iodine-131, a common radioisotope used in medical tracers, has a half-life of 8 days. Estimate how many days it would take for an initial dose of I-131 to decrease to 1% of its original amount.
Between 48-56 days
Which type of radioactive decay is likely to happen to a nucleus with too many neutrons compared to protons?
Beta-negative decay (A neutron will decay into a proton)
a. How many neutrons will be released by this fission reaction? [Show picture]
b. Yes or no: Will this start a chain reaction?
3 neutrons, yes