Which combination of N N\,N and Z Z\,Z gives a nucleus with the largest specific charge?
N=8N = 8N=8, Z=6Z = 6Z=6
N=11N = 11N=11, Z=8Z = 8Z=8
N=15N = 15N=15, Z=11Z = 11Z=11
N=18N = 18N=18, Z=13Z = 13Z=13