aubreyalomar7656 aubreyalomar7656 13-05-2023 Physics contestada 4.+radioactive+decay+the+mass+of+radioactive+material+in+a+sample+has+decreased+by+30%+since+the+decay+began.+assuming+a+half-life+of+1500+years,+how+long+ago+did+the+decay+begin