Question

Which of the following statements are correct with respect to the unit of radioactivity?(i) The SI unit of radioactivity is curie [Ci].(ii) 1 Ci = 3.7 x 10^-10 dps(iii) 1 Bq = 3.7 x 10^-10 Ci(iv) The SI unit of radioactivity is becquerel (Bq).(v) 1 Ci = 3.7 x 10¹⁰ Bq

• (A) (i) and (iii)
• (B) (iv) and (v)
• (C) (i) and (ii)
• (D) (ii) and (iv)

Answer 1

The Correct Option is B

Explanation:
The SI unit of radioactivity is becquerel (Bq). $1\mathrm{Ci}=3.7\times {10}^{10}$ disintegration ${\mathrm{s}}^{-1}$$1\mathrm{Ci}=3.7\times {10}^{10}\mathrm{Bq}$$1\mathrm{Bq}=1$ disintegration ${\mathrm{s}}^{-1}$

Answer 2

The phenomenon of spontaneous emission of radiation by heavy elements is called Radioactivity.

• The elements which show the phenomenon of radioactivity are called radioactive substances.
• Natural elements with atomic numbers more than 82 are unstable and thus radioactive.
• Heavy nuclei have a large number of protons and electrostatic repulsion between the protons badly affects the nuclear force binding the nucleons and thereby makes the heavy nucleus unstable.

Units of Radioactivity

The SI unit of radioactivity is Becquerel (Bq). Curie (Ci) and Rutherford (rd) are also the units of radioactivity.

• 1 Bq = 1 decay per second
• 1 Curie (Ci) = 3.7 x 10¹⁰ Bq
• 1 rutherford (rd) = 10⁶ Bq