i am not able to understand Q value in case of nuclear reactions in HC VERMA and in some places in HC VERMA it is given recoilimg of daughter nucleus, as HC VERMA has not given any information regatrding this, what actually it means. please send me as much as information as you can so that i can clearly understand both. also there is one law in nuclear reactions that total electric charge remains conserved. what actually it means? please also elaborate it as much as you can.