Video Transcript
The following questions relate to
the ability of different types of ionizing radiation to penetrate various
substances. Which type of ionizing radiation is
able to pass through aluminum but is stopped by large quantities of concrete or
several centimeters of lead? (A) 𝛽 particles, (B) 𝛼 particles,
(C) 𝛾 rays.
Ionizing radiation is radiation
that carries enough energy to remove electrons from atoms. 𝛼 particles, 𝛽 particles, and 𝛾
rays are all types of ionizing radiation. 𝛼 particles consist of two
positively charged protons and two neutral neutrons and have the same composition as
a helium nucleus. 𝛽 particles are high-energy
electrons and carry a negative charge. 𝛾 rays are a high-frequency
electromagnetic wave that travels at the speed of light.
Due to the size of the particle, 𝛼
particles have a low penetrating ability and can be stopped by skin, a piece of
paper, or approximately 10 centimeters of air. 𝛽 particles are significantly
smaller than 𝛼 particles and therefore have a greater penetrating ability. 𝛽 radiation can pass through skin
and paper but can be stopped by a thin sheet of aluminum. As 𝛾 radiation has no mass and
travels as a wave of electromagnetic energy, it has the greatest penetrating
ability. It can pass through paper,
aluminum, and most materials. Sheets of lead a few centimeters
thick or a meter or more of concrete are often enough to stop 𝛾 radiation. Understanding which types of
materials can be used to stop different forms of ionizing radiation is important, as
ionizing radiation is harmful to biological systems.
Now that we understand the
difference in penetrating ability between 𝛼, 𝛽, and 𝛾 radiation, let’s return to
the question. Which type of ionizing radiation is
able to pass through aluminum but is stopped by large quantities of concrete or
several centimeters of lead? The correct answer is answer choice
(C) 𝛾 rays.
Which type of ionizing radiation is
able to pass through paper but is stopped by aluminum sheeting? (A) 𝛽 particles, (B) 𝛼 particles,
(C) 𝛾 rays.
Looking at the diagram that we drew
earlier, we can see that the correct answer is answer choice (A). 𝛽 particles can pass through paper
but can be stopped by aluminum sheeting.
Which type of ionizing radiation
could be stopped by a human hand? (A) 𝛽 particles, (B) 𝛼 particles,
(C) 𝛾 rays.
𝛼 radiation has the largest mass
and is the least penetrating of the three types of ionizing radiation shown. It can be stopped by a piece of
paper, skin, or 10 centimeters of air. The type of ionizing radiation that
could be stopped by a human hand is answer choice (B) 𝛼 particles.
