Radioactivity

Free sample questions

Radioactivity — sample Science questions with answers

1. Question 1

   What is meant by radioactivity?

   • AThe process of energy release by stable atoms
   • BThe process of spontaneous emission of radiation by unstable atomic nuclei
   • CThe process of splitting a large atomic nucleus into smaller nuclei
   • DThe process of combining small atomic nuclei to form a larger nucleus

   Answer: B. The process of spontaneous emission of radiation by unstable atomic nuclei

   Radioactivity is the spontaneous process in which unstable atomic nuclei emit radiation (alpha, beta, or gamma) to become more stable.

2. Question 2

   Which of the following is radiation consisting of positive particles?

   • AAlpha radiation ($\alpha$)
   • BBeta radiation ($\beta$)
   • CGamma radiation ($\gamma$)
   • DX-radiation

   Answer: A. Alpha radiation ($\alpha$)

   Alpha radiation consists of 2 protons and 2 neutrons (helium nucleus), which is positively charged. Beta radiation is negatively charged, gamma and X are electromagnetic waves.

3. Question 3

   What is the charge of beta radiation?

   • APositive
   • BNegative
   • CNeutral
   • DDepends on the isotope

   Answer: B. Negative

   Beta radiation is an electron emitted from the nucleus, therefore it is negatively charged.

4. Question 4

   Which of the following radiations has the highest penetrating power?

   • AAlpha radiation
   • BBeta radiation
   • CGamma radiation
   • DNeutron radiation

   Answer: C. Gamma radiation

   Gamma radiation is a highly penetrating electromagnetic wave, capable of penetrating thick concrete. Alpha is weakest, beta is moderate.

5. Question 5

   Radioactive materials are used in medicine to treat cancer. Which radiation is suitable for radiotherapy?

   • AAlpha radiation
   • BBeta radiation
   • CGamma radiation
   • DAll of the above

   Answer: C. Gamma radiation

   Gamma radiation is used to kill cancer cells due to its high penetrating power and can be targeted to deep tissues.