Please helpme with my homework. How to solve thisproblem? Ch17-17 (A) or (B) The
ID: 1727729 • Letter: P
Question
Please helpme with my homework. How to solve thisproblem? Ch17-17 (A) or (B) The carbon in living organisms contains about 1.3 atomsof 14C for every 1012 atoms of allkinds of carbom, and the half-life of 14C is 5730years. (A) How many decays would one expect per minute from 7g ogcarbon taken from a living tree? (B) IF 7g of carbon is extracted from a wooden beam of aprehistoric dwelling and if they undergo 10 decays per minute,about how old is the dwelling? Answer (A) R0 = 105 decays/min Answer (B) 19,400yr Please helpme with my homework. How to solve thisproblem? Ch17-17 (A) or (B) The carbon in living organisms contains about 1.3 atomsof 14C for every 1012 atoms of allkinds of carbom, and the half-life of 14C is 5730years. (A) How many decays would one expect per minute from 7g ogcarbon taken from a living tree? (B) IF 7g of carbon is extracted from a wooden beam of aprehistoric dwelling and if they undergo 10 decays per minute,about how old is the dwelling? Answer (A) R0 = 105 decays/min Answer (B) 19,400yr (A) How many decays would one expect per minute from 7g ogcarbon taken from a living tree? (B) IF 7g of carbon is extracted from a wooden beam of aprehistoric dwelling and if they undergo 10 decays per minute,about how old is the dwelling? Answer (A) R0 = 105 decays/min Answer (B) 19,400yrExplanation / Answer
7g, 7/12 mole, 7/12*6.023*1023 carbon atoms,7/12*6.023*1023*1.3/1012 carbon 14 atoms,so N0 = 7/12*6.023*1023*1.3/1012 half-life T = 5730 yr = 5730*365*24*60 min, decay constant =ln(2)/T a) R0 = N0 = 105 decay/min b) R = 10 decay/min R = N = N0e-t =R0e-t t = 1/ ln(R0/R) = T*ln(R0/R)/ln(2) = 5730*ln(105/10)/ln(2) = 19438 yr.