Correct the following sentence: O 15 + n 0 1 8 → C 13 6 + H 2 e 4

The subscript of an element represents the atomic number whereas the superscript represents the mass number. In a nuclear reaction, the mass number of the reactants and the products should be equal. However, in the following reaction, the mass number on both sides are not equal. O 15 + n 0 1 8 → C 13 6 + H 2 e 4 To make the mass number equal, we need to balance the reaction so that the mass number becomes equal on both sides. ∴ O 15 + 2 n 0 1 8 → C 13 6 + H 2 e 4 .

Correct the following sentence: 1 MeV = 1 . 6 × 10 - 15 J

Electron volt is a unit of energy. It is represented by eV . 1 eV is defined as the amount of kinetic energy gained by an electron when it accelerates through an electric potential difference of 1 V . 1 eV = 1 . 6 × 10 - 19 J Since this unit is very small, sometimes it is convenient to use mega electron volt. 1 MeV = 10 6 × 1 eV ∴ 1 MeV = 10 6 × 1 . 6 × 10 - 19 J ⇒ 1 MeV = 1 . 6 × 10 - 13 J

Correct the following sentence: 1 curie = 3 . 7 × 10 8 decays / second .

A substance is said to be highly radioactive when it has a very high rate of decay i.e, the number of decays per unit time is very high. R = ∆ N ∆ t where R is the rate of decay and ∆ N is the number of decays in ∆ t time. The SI unit of activity is Becquerel. 1 Bq = 1 decay / second . Another common unit of activity is Curie. 1 Ci = 3 . 7 × 10 10 decays / second . Another important unit of activity is Rutherford. 1 Rd = 10 6 decays / second .