A nuclear isotope emits radiation which is detected by a Geiger-Müller tube held at a distance of
about 10cm from the radioactive source. The radiation is stopped completely by a 2mm thick
sheet of lead.
What can be deduced from this information about the emission from the isotope?
A It could be alpha and beta radiation, but not gamma radiation.
B It could be alpha and gamma radiation, but not beta radiation.
C It could be beta and gamma radiation, but not alpha radiation.
D It could be alpha, beta and gamma radiation.

Question

A nuclear isotope emits radiation which is detected by a Geiger-Müller tube held at a distance of 
about 10cm from the radioactive source. The radiation is stopped completely by a 2mm thick 
sheet of lead. 
What can be deduced from this information about the emission from the isotope? 
A It could be alpha and beta radiation, but not gamma radiation. 
B It could be alpha and gamma radiation, but not beta radiation. 
C It could be beta and gamma radiation, but not alpha radiation. 
D It could be alpha, beta and gamma radiation.

anonymous · Answer

The answer is A
Alpha because Although alpha particles cannot penetrate the skin, if it gets into the body it can ionise many atoms in a short distance.
Beta because Beta particles are much more penetrating and can travel easily through skin. These particles are stopped by lead

rane · Answer

its A @blackilluminati is correct