Ar is the basis of a common system for dating rocks. The standard K-Ar courting process depends upon the assumption which the rocks contained no argon at some time of development and that each one the subsequent radiogenic argon (40S?n ph?m c?a công ty mang th??ng Hello?u HADICO TH?NG LONG là d??ng ch?t th?c s? cho cây tr?ng g?n g?i v?i thiên n