Match each description to a type of radiation. Drag each item to the appropriate bin.
mass – 4 amu
deepest penetration
charge 1
mass – 1/2000 amu
charge = 0
charge = +2
medium penetration
mass – 0 amu
least penetration
hray
sparticle
b particle
The Correct Answer and Explanation is:
Here’s the correct match between each description and the type of radiation:
Alpha (α) particle:
- mass – 4 amu
- charge = +2
- least penetration
Beta (β) particle:
Gamma (γ) ray:
- mass – 0 amu
- charge = 0
- deepest penetration
Explanation (300+ words):
Radiation comes in different types, and each has unique properties regarding mass, charge, and ability to penetrate materials. The three main types of radiation emitted by radioactive substances are alpha particles (α), beta particles (β), and gamma rays (γ).
Alpha particles consist of 2 protons and 2 neutrons, giving them a mass of about 4 atomic mass units (amu). They carry a +2 positive charge. Due to their relatively large mass and strong charge, they interact heavily with matter and are easily stopped, even by a sheet of paper or the outer layer of human skin. Therefore, they have the least penetration ability but are very dangerous if ingested or inhaled.
Beta particles are high-speed electrons or positrons ejected from a decaying atomic nucleus. Since electrons have negligible mass compared to protons and neutrons, beta particles are described as having a mass of 1/2000 amu. They carry a negative charge (-1), although sometimes the charge is just referenced as magnitude, i.e., “charge 1”. Beta particles can penetrate more deeply than alpha particles but are still stopped by materials like plastic or a few millimeters of aluminum. Hence, they are classified as having medium penetration.
Gamma rays are a type of electromagnetic radiation, similar to X-rays but with higher energy. Since they are pure energy with no mass or charge, they are listed as having 0 amu mass and charge = 0. Gamma rays are extremely penetrating and can travel through several centimeters of lead or several meters of concrete. This property makes them the most penetrating and the most difficult to shield against.
To summarize:
- Alpha: heavy and charged, easily stopped.
- Beta: light and charged, moderately penetrating.
- Gamma: massless and neutral, deeply penetrating.
Understanding these properties is critical in nuclear medicine, radiation safety, and environmental health.