Question

What particle is needed to complete this nuclear reaction? 222 86 rn 218po?

Answer 1

The particle needed to complete the nuclear reaction 222 Rn → 218 Po is an alpha particle (He). The resulting balanced nuclear equation is 222 Rn → 218 Po + 4 He with a significant amount of gamma ray energy released.

Step-by-step explanation:

The particle needed to complete the nuclear reaction 222 Rn → 218 Po is an alpha particle, which is represented by He. In alpha decay, a radioactive nucleus emits an alpha particle and transforms into a new nucleus with a mass number that is reduced by four units and an atomic number that is reduced by two units. Hence, we use subtraction (222 - 4 = 218 and 86 - 2 = 84) to identify the daughter isotope of polonium, 218 Po. The complete balanced nuclear equation for the decay of radon-222 by alpha particle emission is:

222 Rn → 218 Po + 4 He
86 84 2

This nuclear reaction also releases gamma ray energy, which although not much for a single atom, would result in a significant amount of energy if one mole of Rn atoms were to decay—approximately 4.9 × 107 kJ.

Answer 2

Nuclear reaction involved in present case is

222 86 Rn → 218 84 Po + X

Step 1: Balancing Atomic Number:
On reactant side atomic number is 86. On product side atomic number is 84. Hence, atomic number of X is 86 - 84 = 2

Step 2: Balancing atomic mass number:
On reactant side atomic number is 222. On product side atomic number is 218. Hence, atomic number of X is 222-218 = 4

Therefore, element X has atomic number 2 and atomic mass number 4. This corresponds to He.

Hence complete reaction is
222 86 Rn → 218 84 Po + 4 2 He