Mod 15 Flashcards
(22 cards)
What are the different types of radiation?
α, β, γ, positron, neutron
Each type carries characteristic mass, charge, and penetrating power.
What is the mass and charge of alpha radiation?
Mass: 4, Charge: 2⁺
Alpha particles are stopped by paper.
What is beta radiation?
High-energy electron with charge 1⁻
Stopped by lab coat or plastic.
What is a positron?
Same mass as β but charge 1⁺
Used in PET scans.
What is gamma radiation?
Pure energy requiring lead or concrete shielding
It has the highest penetrating power.
Order the penetrating power of radiation types from least to most penetrating.
α < β < γ
This order reflects the effectiveness of shielding.
What biological effects does ionizing radiation have?
Removes electrons, creating ions that damage cells
Fast-dividing tissues are highly sensitive.
What are key protection strategies against radiation?
Limit exposure time, increase distance, use shielding
Specific shielding includes paper for α, heavy clothing for β, and lead/concrete for γ.
How do you balance nuclear equations?
Conserve mass and atomic numbers
Determine unknown particle by difference in A and Z.
What happens in alpha decay?
A −4, Z −2
Example: Rn-198 α-decay → ¹⁹⁴₈₄Po + ⁴₂He.
What happens in beta decay?
Z +1
Example: U-237 β-decay → ²³⁷₉₃Np + ⁰₋₁e.
What is the purpose of Geiger counters?
Detect β/γ via ionization
Used for measuring radiation levels.
What is the conversion for 1 Ci?
1 Ci = 3.7×10¹⁰ Bq
Bq stands for Becquerel, a unit of radioactivity.
What does 1 Gy equal in rad?
1 Gy = 100 rad
Gy stands for Gray, a unit of absorbed dose.
What is the formula for calculating remaining mass after decay?
Remaining mass = initial × (½)ⁿ
Where n = elapsed time/t½.
What is the significance of short half-life isotopes in medicine?
Ideal for imaging to minimize patient dose
They reduce radiation exposure.
What is the half-life of Tc-99m?
6 hours
Used for bone and heart scans.
What is nuclear fission?
Splitting heavy nuclei, releasing energy & neutrons
It can lead to chain reactions.
What is nuclear fusion?
Merging light nuclei at extreme temperatures, producing enormous energy
Occurs in stars.
What is critical mass?
Minimum quantity for a self-sustaining chain reaction
Essential for maintaining fission reactions.
Fill in the blank: ¹¹₆C → ______ + ⁴₂He.
⁷₄Be
This is an example of a nuclear reaction.
How much I-123 remains from 64 mg after 26 h?
16 mg
This is calculated using the half-life formula.
