Question

Which represents the balanced nuclear equation for the beta minus decay of Co-60?
Superscript 60 subscript 27 upper C o right arrow superscript 60 subscript 26 upper F e plus superscript 0 subscript plus 1 e.
Superscript 60 subscript 27 upper C o right arrow superscript 60 subscript 28 upper N i plus superscript 0 subscript negative 1 e.
Superscript 60 subscript 27 upper C o plus superscript 0 subscript plus 1 e right arrow superscript 60 subscript 28 upper N i.
Superscript 60 subscript 27 upper C o plus superscript 0 subscript negative 1 e right arrow superscript 60 subscript 26 upper Fe.

Answer 1

The second equation is correct:

^60_27Co → ^60_28Ni + ^0_-1e

Reason: In β− decay a neutron converts to a proton and an electron, so A (60) stays the same and Z increases by 1 (27 → 28); the emitted electron carries the −1 charge.