In an ancient rock sample of mass m, it is estimated that there are a gram of radiocarbon 1Celement and b gram of stable 1c element. If the core half-life of 13C is Tm = 5760 years, (I). Explain the procedure for determining the age of the rock. (It). Determine the mass ratio; m14c : \"'12.: at the current moment, if the current activity 1C remains 75% of the initial activity. Answers are expressed in known variables. [Avogadro's number N = 6.02 x 1023particleslmoi, mm: 14 gramsfmol and 11112: = t2 gramsi'mol]