Video Transcript
Which of the following is the
correct descending order of different types of radiation according to their
penetration power? (A) 𝛼 particles, 𝛽 particles, 𝛾
rays. (B) 𝛼 particles, 𝛾 rays, 𝛽
particles. (C) 𝛽 particles, 𝛼 particles, 𝛾
rays. (D) 𝛾 rays, 𝛼 particles, 𝛽
particles. (E) 𝛾 rays, 𝛽 particles, 𝛼
particles.
In this question, we are asked to
compare and order different types of radiation according to their penetration
power. If we look at the answer choices,
the types of radiation listed include 𝛼 particles, 𝛽 particles, and 𝛾 rays. The different particles and the 𝛾
rays all have different penetrating abilities, which is related in part to their
size.
𝛼 particles are large and consist
of two protons and two neutrons. As 𝛼 particles are large, they
have low penetrating ability and can be stopped by a piece of paper. 𝛽 particles are high-energy
electrons or positrons. 𝛽 particles travel much faster
than 𝛼 particles and are significantly smaller. They can pass through a piece of
paper but are stopped by a thin sheet of aluminum. 𝛾 rays, or 𝛾 radiation, are
high-frequency electromagnetic waves that travel at the speed of light. 𝛾 rays do not have mass and can
pass through most materials. It requires a few centimeters of
lead or over a meter of concrete to stop 𝛾 rays.
If we now order these types of
radiation in descending order from greatest penetration power to least, we get 𝛾
rays followed by 𝛽 particles followed by 𝛼 particles. In conclusion, the answer choice
that lists the different types of radiation in descending order according to their
penetration power is answer choice (E) 𝛾 rays, 𝛽 particles, 𝛼 particles.
