Y are Z=11---> 11 e pe invelisul electronic si 11 protoni in nucleu
are A=23---> A=11protoni + 12 neutroni, deci in nucleu sunt 11 protoni si 12 neutroni
Q are Z=17---> are 17e pe invelisul electronic si 17 protoni in nucleu
are A=35---> A= 17 protoni +18 neutroni, deci in nucleu sunt 17 protoni si 18 neutroni