Question

(b) Write the two nuclear equations that are the basis for the radio-dating process that is based on carbon-14 (c) What types of materials can be radio-dated using carbon-14? (d) Briefly explain how the carbon-14 dating method works. (e) Radioisotope dating depends on constant rate of decay and formation of various nuclides in a sample. How is the proportion of carbon-14 kept relatively constant in organisms ? (f) How old does a sample have to be before the carbon dating methods becomes unreliable ? (g) A Geiger counter measures the radioactivity of carbon-14 in a living plant sample at 15.4 disintegration's per second. If the half-life of carbon-14 is 5,715 years, how old is a scroll found in the Dead Sea area of the Middle East if the Geiger counter measured it's carbon-14 radioactivity at 11.5 disintegration's per second? (h) Plutonium-239 (a emitter, t12 2.41x101 years) represents a serious nuclear waste hazard. If it takes seven half-lives until only ~ 1% of original plutonium-239 remains, how long must 29Pu be stored before it reaches that level?

Answer 1

b) Nucleah heack ons at are basis Jol γ0diodakng ane 14 14 )1 uood, peat , Jossil, onganic maleviol nj present in soil clot, paper, hides can be ½adio dared using , bones eb d) C is-tope is ouch abundant (98.99%), 7he is o ope in tRe almesphese by neulron bombadment on cabon is only Jound in aces 'As a hesuyualion, Cin ans. b) , tic and CO pnesent i antil e almosphexe has been a constar.sth's,"co consumed by Plant and animals alona w鴻 lhe concenbration Ss Constant. C in all Kii canno a↓mosphere. The 't: contenLint eplan

Sample = 15-4 dibinlegalitas) sec k 0.693 yeas 5지S kb In 11-5 ユー0.693 t 15.H .5チIS 5チIS 0.69 3 k 0.63 .303 Xog o. Is o.693 One