Mode of decay for unstable nuclides

Question

Predict a likely mode of decay for each unstable nuclide. Write its balanced nuclear reaction.

a) Mo-109

b)Ru-90

c) P-27

d) Rn-196

Answer 1

β

Predicted likely mode of decay:

a)    Mo-109: Heavier isotope of normal Mo atom amu 96,

decays electron emission β (-1) particle

 ¹⁰⁹Mo =>¹⁰⁹Tc + β(-1) =>¹⁰⁹Ru + β(-1)=>¹⁰⁹Rh + β(-1) =>¹⁰⁹Pd + β(-1)=>¹⁰⁹Ag + β(-1)

other likely mode

 ¹⁰⁹Mo => ¹⁰⁹Tc + β (-1) => ¹⁰⁸Ru + β (-1) + neutron => ¹⁰⁸Rh + β (-1) => ¹⁰⁸Pd + β (-1)

b)   Ru-90: Lighter isotope of normal Ru atom amu 101,

decays positron emission β (+1) particle

Equation: ⁹⁰Ru => ⁹⁰Tc +β (+1) => ⁹⁰Mo + β (+1) => ⁹⁰Nb + β (+1) => ⁹⁰Zr + β (+1)

c)    P-27: Lighter isotope of normal P atom amu 31,

decays positron emission β (+1) particle

Equation: ²⁷P => ²⁷Si + b (+1) => ²⁷Al + β (+1) other likely mode

                 ²⁷P => ²⁶Al + β (+1) + Proton=> ²⁶Mg + β (+1)

d)   Rn-196: Lighter isotope of normal Rn atom amu 222,

decays positron emission β (+1) particle

Equation: ¹⁹⁶Rn => Several decay modes => ¹⁸⁸Os + β (+1) Most abundant final product Os

Refer to link: https://periodictable.com/Isotopes/086.196/index2.full.dm.prod.html

I hope this helps.

Sincerely

Shailesh (Sky) K., Expert Tutor at WYZANT

Former Professor, University of Pittsburgh Johnstown PA