Question

The half-life for the radioactive decay of C-14 is 5730 years. You may want to reference (Pages 598 - 605) Section 14.5 while completing this problem.

Exercise 14.58 - Enhanced with Feedback 26 of 48 Review I Constants I Periodic Table The half-life for the radioactive decay of C-14 is 5730 years Part A You may want to reference (Pages 598 605) Section 14.5 while completing this problem. How long will it take for 30% of the C-14 atoms in a sample of C-14 to decay? Express your answer using two significant figures. nνα ΑΣφ VA dD ? t= years Request Answer Submit Part B If a sample of C-14 initially contains 1.9 mmol of C-14, how many millimoles will be left after 2235 years? millimoles using two significant figures. Express your answer | ΑΣφ VA mmol Request Answer Submit Provide Feedback Next

Answer 1

All radioactive decay processes follows first order kinetics.

a = initial concentration.

Fisust ostdesi ate constant is given as, t (a-n)

a-x = concentration after time 't'

Half-lite is given as, ts balar 0.693 tve k thy =5730 ys a= loo% PR (a- = 100-30 = 70% k=0.693 5730 S88 X10 Dreep/crotx01e =o) n 100 t O.693 than 70 5730 t 5730 In 1429 O.693 t=5730 x 0-357 O.693 H4O! t2951-81 yeass a=1.9mmol LD Bk 0.693 t 2235 ys 5730 In 1-9 0.693 2235 5730 elsoo. 22 35 X0-693 In1.9-Inca-x) 5730 0.642,- Inla-x) 0.270 -In(a-x)0.270 - 0-642 Inca-a)=0.372 (a-) = eo372 (a-x)= 1.5 mmol