Atomic Structure Summary review Flashcards
(22 cards)
Draw a diagram showing the structure of an atom.
(Answer on google classroom)
What is an isotope?
A different version of an atom for an element with the same number of protons but different numbers of neutrons
How many protons and neutrons are found in a normal carbon nucleus?
6 protons, 6 neutrons and 12 is the mass number
How many protons and neutrons are found in the nucleus of a carbon-14 isotope?
6 protons, 8 neutrons and it’s mass number is 14
What is ionization?
Radiation removing an electron from an atom or molecule, changing it
Describe alpha radiation
2 protons and 2 neutrons
Describe beta radiation
High speed electron
Describe gamma radiation
Electromagnetic waves
Complete the table showing the properties of the 3 types of radiation
Alpha. Beta. Gamma.
Mass. . 4. Very Small. None
Charge. +2. -1. None
Absorbed by Skin/paper. Aluminum. Lead
Complete the diagram showing how alpha, beta and gamma travel through an electric field
(Answer on google classroom)
Write the decay equation for Radium 226 (alpha decay)
- Ra. ➡️ a +. Rn.
- 86.
- Ra. ➡️ a +. Rn.
Write the decay equation for Polonium 218 (beta decay)
- Po. ➡️ e. . +. At
84. -1. 85
- Po. ➡️ e. . +. At
What is half-life?
The time taken for the amount of radiation from a source to decrease by half
Sketch a graph showing a half-life of 2 days.
(Answer on google classroom)
Strontium 90 has a half-life of 28 years. How long will it take to fall to less than 1% of it’s original activity?
0 years = 100%
28 years (1 half life) = 50%
56 years (2 half lives) = 25%
…
196 years (7 half-lives) = 0.78%
The activity of a sample of Uranium 235 is 640 Bq. Two hours later it has fallen to 40 Bq. What is its half-life?
640 → 40 = 4 half lives
4 half lives in 120minutes (two hours) Half life = 30 minutes
What is nuclear fission?
Splitting a nucleus releasing energy
What is nuclear fusion?
Joining two nuclei together releasing energy
What is the difference between contamination and irradiation?
Irradiation = Exposure to radiation from a source that is outside your body
Contamination = Exposure to radiation from a source that is inside your body
What is background radiation?
Radiation that is always in the atmosphere from cosmic rays, rocks, radon gas and other sources
Describe how radiation can be used to measure thickness
A radioactive source is placed on one side of the item and a detector on the other. Alpha can be used to measure paper thickness, beta can be used for metals. The thickness of the material will affect the amount of radiation detected on the other side.
Describe how radiation can be used as a medical tracer
The patient eats/drinks or is injected with a radioactive source. After a few hours a camera which detects radiation is used to scan the body. Radiation will be emitted from wherever the source has travelled (eg through the digestive system)
