# Use the fact that after 5715 years a given amount of carbon 14 will have decayed to half the original amount to find the exponential decay model for carbon 14. In 1947, earthenware jars containing what was known as the

34,632 results
1. ## calculus

A sample of a radioactive substance decayed to 94.5% of its original amount after a year. (Round your answers to two decimal places.) (a) What is the half-life of the substance? (b) How long would it take the sample to decay to 65% of its original amount?

2. ## Science

Radioactive carbon-14 dating has determined that a fossil is 5.7 x 10 to the third power years old. What is the total amount of the original Carbon-14 still present in the fossil?

3. ## calculus

Carbon-14 is a radioactive substance produced in the Earth's atmosphere and then absorbed by plants and animals on the surface of the earth. It has a half-life (the time it takes for half the amount of a sample to decay) of approximately 5730 years. Using

4. ## Calculus

For the decomposition of Carbon 14, find the age of a prehistoric cave painting discovered in the Lascaux Caves in southern France if the amount of Carbon 14 has decayed to 14.29%...again using calculus formulas. Not sure how to use this equation (content

5. ## exponential function

An investment pays 8% interest, compounded annually. a) write an equation that expresses the amount, A, of the investment as a function of time, t, in years. b) determine how long it will take for this investment to double in value and then to triple in

6. ## Chemistry

The cloth shroud from around a mummy is found to have a carbon-14 activity of 8.1 disintegrations per minute per gram of carbon as compared with living organisms that undergo 15.2 disintegrations per minute per gram of carbon. From the half-life for

7. ## Calc

A sample of a radioactive substance decayed to 93.5% of its original amount after a year. a) What is the half-life of the substance? ? years (b) How long would it take the sample to decay to 10% of its original amount? ? years

8. ## algebra

Use the fact that after 5715 years a given amount of carbon 14 will have decayed to half the original amount to find the exponential decay model for carbon 14. In 1947, earthenware jars containing what was known as the Dead Sea scrolls were found by an

9. ## Physics

Could someone help explain this problem to me . . . Carbon 14 has a half-life of 5700 year, scientist use this fact to determine the age of things made of organic material. Suppose the average page of a book containing aprox. 0.5mg of Carbon 14 is put into

10. ## math

the half life of the carbon isotope C14 is about 5700 years. A. about how many years does it take 1000 grams of this substance to decay to 500 grams? B. about what percent of the original amount would you expect to find after 1000 years?

An artifact originally had 16 grams of carbon-14 present. The decay model A = 16e -0.000121t describes the amount of carbon-14 present after t years. How many grams of carbon-14 will be present in 5715 years? A. Approximately 7 grams B. Approximately 8

12. ## algebra

carbon 14 has a hlf life of 5700 years. scientists use this fact to determine the age of things made up of organic material. Suppose the average page of a book containing approximitly .5 mg og carbon 14 was put into a time capsule. How much carbon14 will

13. ## chemistry

A 1.00-g sample of carbon from a modern source gave 15.3 disintegrations per minute. A sample of carbon from an “old” source gave 920 disintegrations per hour. What is the age of the “old” sample of carbon? The half-life of carbon-14 is 5.73×103

14. ## physics

A wooden artifact is found in an ancient tomb. Its carbon-14 activity is measured to be 60.0% of that in a fresh sample of wood from the same region. Assuming the same amount of carbon-14 was initially present in the wood from which the artifact was made,

15. ## Chemistry

carbon 14 has a half life of 5715 years. If you start with a 5 gram sample of 14C, what mass is left after 15,000 years?

16. ## Algebra 2

Carbon Dating: Use the formula y= ae^-.00012t where a is the initial amount of carbon-14 , t is the number of years ago the animal lived, and y is the remaining amount after t years how old is a fossil remain that has lost 95% of its carbon-14

17. ## Chemistry

An archeological artifact was subjected to radiocarbon dating. The artifact showed a carbon-14 decay rate of 13.8 disintegrations/ min per gram of carbon. Carbon-14 has a half-life of 5715 years, and currently living organisms decay at the rate of 15.3

18. ## Calculus

The amount of carbon-14 still present in a sample after t years is given by the function where C0 is the initial amount. Estimate the age of a sample of wood discovered by an archeologist if the carbon level in the sample is only 18% of its original

19. ## algebra

Scientists can determine the age of ancient objects by a method called radio carbon dating. The bombardment of the upper atmosphere by cosmic rays converts nitrogen to a radioactive isotope 14C of carbon with a half-life of about 5710 years. Vegetation

20. ## Science

Radioactive substance decays so that after t years, the amount remaining, expressed as a percent of the original amount, is A(t)=100(1.6)^(-t). a) Determine the function A’, which represent the rate of decay of the substance. b) what is the half-life for

21. ## calculus

radioactive Carbon 14 in a dead organism decays according to the equation A=A e^.000124t where t is in years and A0 is the amount at t=0. Estimate the age of a skull uncovered in an archeological site if 10% of the original Carbon 14 is still present.

22. ## Homework test

An artifact was found and tested for its carbon-14 content. If 70% of the original carbon-14 was still present, what is its probable age (to the nearest 100 years)? Use that carbon-14 has a half-life of 5,730 years.

23. ## math

An artifact was found and tested for its carbon-14 content. If 83% of the original carbon-14 was still present, what is its probable age (to the nearest 100 years)? Use that carbon-14 has a half-life of 5,730 years.

24. ## Biology

The half life of carbon 14 is 5700 years. If the carbon 14 level measured in a fossilized bone has only 1/4 of the original amount, how old in the bone?

25. ## Math

A bone is found to have 45% of the original amount of carbon 14. If the half life of carbon is 5600 years, how old is the bone. Would I use the formula N=No e^kt?

26. ## science

The half-life of carbon-14 is 5730 years. If we start with 10 grams of carbon-14, after 5730 years, we will have _____ of carbon-14 left.

27. ## Calc

Set up an exponential function to model each real world situation then use it to find the requested values. The half-life of Carbon 14 is about 5700 years. You begin with 800 grams of this isotope. 1) Function: 2) How much Carbon 14 is there after: a)

28. ## Physics

The isotope carbon-14, 146C, is radioactive and has a half-life of 5730 years. If you start with a sample of 1000 carbon-14 nuclei, how many will still be around in 22920 years? I got 62.5 atoms, am I correct?? Thank you!!

29. ## Chemistry

How much a 2.00 g 239 Pu would have decayed after 1.6 x 10^4 years? The half-life for 239 Pu is 2.4 x 10^4 years. amount remaining= originalamount*(.5)^(1.6/2.4) amount decayed = original - amountremaining

30. ## calculus BC

Carbon-14 decay (radiocarbon dating) is used in archaeology to measure the age of ancient pottery. Carbon-14 has a half-life of 5830 years. How old is a pot in which 20% of the Carbon-14 has decayed?

31. ## Chemistry

Carbon-14 has a half-life of 5730 years In a plant fossil you find that the 14 C has decayed to 1/8 of the original amount how long ago was this plant

32. ## CALCULUS

3.Using the curve that you constructed for the decomposition of Carbon 14, find the age of a prehistoric cave painting discovered in the Lascaux Caves in southern France if the amount of Carbon 14 has decayed to 14.29%

33. ## Algebra 2/ Chemistry?

Carbon Dating: Use the formula y= ae^-.00012t where a is the initial amount of carbon-14 , t is the number of years ago the animal lived, and y is the remaining amount after t years how old is a fossil remain that has lost 95% of its carbon-14

34. ## science

my teacher gave us this question and im lost. Anthropologists have found an old campsite in a remote location. After calculating the carbon-14 in the wood, they determine that there is 1/8 of the original material left. How many half-lives of carbon-14

35. ## math: pre-calculus

You have 5 grams of carbon-14; whose half-life is 5730 years. a)Write the rule of the function that gives the amount of carbon-14 remaining after x years. b)How much carbon-14 will be left after 4,000 years? c)When will there be just 1 gram left?

36. ## Maths

May someone help me with my HW problem (b)? Radiocarbon dating can be used to estimate the age of material, such as animal bones or plant remains, that comes from a formerly living organism. When the organism dies, the amount of carbon-14 in its remains

37. ## Math

Cosmic ray bombardment of the atmosphere produces neutrons, which in turn react w/ nitrogen to produce radioactive carbon-14. Radioactive carbon-14 enters all living tissue through carbon dioxide. As long as it is alive, carbon-14 is maintained in the

38. ## pre calculus

The age of a document is in dispute, so archaeologists test for carbon-14. Due to radioactive decay, the amount A of carbon -14 present compared to the initial amount A0 after t years is given by the formula A(t) = A0e^-0.000124t . If 72% of the original

By comparing the amount of carbon-14 to amount of carbon-12, one can determine approx how long ago the organism died. The half-life of carbon-14 is 5730 years. Assume the initial quantity of carbon-14 is 600 milligrams. the equation is A (t)=600*(.5)^(t)

40. ## chemistry

Carbon-14 has a half-life of 5730 . In a plant fossil, you find that the has decayed to 1/32.0 of the original amount. How long ago was this plant alive?

41. ## Math

Cosmic ray bombardment of the atmosphere produces neutrons, which in turn react with nitrogen to produce radioactive carbon-14. Radioactive carbon-14 enters all living tissue through carbon dioxide (via plants). As long as a plant or animal is alive,

42. ## Math

In a recent dig, a human skeleton was unearthed. It was later found that the amount of 14C in it had decayed to (1/rt8) of its original amount. If 14C has a half life of 5760 years,how old was the skeleton?

43. ## nuclear chem

i need help solving this. Can you guys show me how it's done. Radium-226 decays by alpha emission to radon-222, a noble gas.What volume of pure Radon- 222 at 23oC and 785mmHg could be obtained from 543.0 mg of radium bromide,RaBr2 in a period of 20.2

44. ## college calculus

the amount of carbon-14 in a mammoth's bone is 45% of the amount found in a living organism. How long ago did the mammoth die? the half-life of carbon-14 is about 5,730 years.

45. ## science

Please help me with this question.... The isotope caesium-137, which has a half-life of 30 years, is a product of nuclear power plants. How long will it take for the amount of this isotope in a sample of caesium to decay to one-sixteenth of its original

46. ## Science

What does a model of the rock cycle show? the amount of earths carbon is constant ←←?? the amount of earths carbon increases the amount of earths carbon decreases the amount of earths carbon cannot be determined

47. ## PreCalculus

The half life of Carbon-14 is 5730 years. a. find the rule of the function that gives the amount remaining from an initial quantity of 100 milligrams of carbon14 after t years. b. the burial cloth of an egyptian mummy i sestimated to contain 59% of the

48. ## Biology

The half-life of Carbon-14 is 5730 years. What is the age of a fossil containing 1/16 the amount of Carbon-14 of living organisms? Explain your calculation.

49. ## Math

A fossilized leaf contains 21% of its normal amount of carbon 14. How old is the fossil (to the nearest year)? Use 5600 years as the half-life of carbon 14.

50. ## chemistry

A 1.00-g sample of carbon from a modern source gave 15.3 disintegrations per minute. A sample of carbon from an “old” source gave 920 disintegrations per hour. What is the age of the “old” sample of carbon? The half-life of carbon-14 is 5.73×103

51. ## Calculus Help Please!!! URGENT!!!!

Carbon-14 has a half-life of 5700 years. In a living organism, the ratio of radioactive carbon-14 to ordinary carbon remains fairly constant during the lifetime of the organism. After the organism’s death no new carbon is integrated into the organism’s

52. ## Science

A material has 32 atoms in all; 24 decayed and the rest undecayed. If the half-life of the radioactive material is 1000 years, what is the age of the material? a. 1000 years b. 2000 years c. 3000 years d. 4000 years

53. ## math: pre-calculus

If current rates of deforestation and fossil fuel consumption continue, then the amount of atmospheric carbon dioxide in parts per million (ppm) will be given by f(x)=375e^0.00609c, where c=0 corresponds to 2000. a)What is the amount of carbon dioxide in

54. ## math

An artifact was found and tested for its carbon-14 content. If 79% of the original carbon-14 was still present, what is its probable age (to the nearest 100 years)? (Carbon-14 has a half-life of 5,730 years.)

55. ## math

An artifact was found and tested for its carbon-14 content. If 83% of the original carbon-14 was still present, what is its probable age (to the nearest 100 years)? Use that carbon-14 has a half-life of 5,730 years.

56. ## Math

An artifact was found and tested for its carbon-14 content. If 88% of the original carbon-14 was still present, what is its probable age (to the nearest 100 years)? Use that carbon-14 has a half-life of 5,730 years. ? yr

57. ## applied algebra

An artifact was found and tested for its carbon-14 content. If 74% of the original carbon-14 was still present, what is its probable age (to the nearest 100 years)? Use that carbon-14 has a half-life of 5,730 years. 1 yr

58. ## Algebra

An artifact was found and tested for its carbon-14 content. If 74% of the orginal carbon-14 was still present, what is its probable age (to the nearest 100 years)? (Carbon-14 has a half life of 5730 years).

59. ## algebra

An artifact was found and tested for its carbon-14 content. If 84% of the original carbon-14 was still present, what is its probable age (to the nearest 100 years)? Use that carbon-14 has a half-life of 5,730 years.

60. ## math

An artifact was found and tested for its carbon-14 content. If 76% of the original carbon-14 was still present, what is its probable age (to the nearest 100 years)? (Carbon-14 has a half-life of 5,730 years.)

61. ## algebra

An artifact was found and tested for its carbon-14 content. If 79% of the original carbon-14 was still present, what is its probable age (to the nearest 100 years)? Use that carbon-14 has a half-life of 5,730 years.

62. ## math

An artifact was found and tested for its carbon-14 content. If 76% of the original carbon-14 was still present, what is its probable age (to the nearest 100 years)? Use that carbon-14 has a half-life of 5,730 years.

63. ## Can some guide me

An artifact was found and tested for its carbon-14 content. If 71% of the original carbon-14 was still present, what is its probable age (to the nearest 100 years)? (Carbon-14 has a half-life of 5,730 years.)

64. ## College Math

An artifact was found and tested for its carbon-14 content. If 88% of the original carbon-14 was still present, what is its probable age (to the nearest 100 years)? Use that carbon-14 has a half-life of 5,730 years.

65. ## Algebra

An artifact was found and tested for its carbon-14 content. If 75% of the original carbon-14 was still present what is its probable age to the nearest 100 years?. carbon -14 has a half-life of 5,730 years.

66. ## Algebra

An artifact was found and tested for its carbon-14 content. If 77% of the original carbon-14 was still present, what is its probable age (to the nearest 100 years)? Use that carbon-14 has a half-life of 5,730 years.

67. ## algebra

An artifact was found and tested for its carbon-14 content. If 84% of the original carbon-14 was still present, what is its probable age (to the nearest 100 years)? Use that carbon-14 has a half-life of 5,730 years.

68. ## Algebra

An artifact was found and tested for its carbon-14 content. If 76% of the original carbon-14 was still present, what is its probable age (to the nearest 100 years)? (Carbon-14 has a half-life of 5,730 years.)

69. ## algebra

An artifact was found and tested for its carbon-14 content. If 75% of the original carbon-14 was still present, what is its probable age (to the nearest 100 years)? (Carbon-14 has a half-life of 5,730 years.) thank you

70. ## math

An artifact was found and tested for its carbon-14 content. If 88% of the original carbon-14 was still present, what is its probable age (to the nearest 100 years)? Use that carbon-14 has a half-life of 5,730 years.

71. ## math

An artifact was found and tested for its carbon-14 content. If 81% of the original carbon-14 was still present, what is its probable age (to the nearest 100 years)? Use that carbon-14 has a half-life of 5,730 years. yr

72. ## physics

You are on an archaeological dig and discover a strange artifact. It is a utensil that appears to be carved out of an elephant's tusk You analyze it and discover that it has 0.625 the amount of carbon-14 you would find in a living specimen. 1.How many

73. ## Physics

(a)-A fossilised tree was tested and contains 10 grams of Carbon-14. Given that there was 12 grams of Carbon-14 present when it died, determine the age of the fossil? Half life of Carbon-14 is 5700 years. (b)How much Carbon-14 will be present in the sample

74. ## Physics

(a)-A fossilised tree was tested and contains 10 grams of Carbon-14. Given that there was 12 grams of Carbon-14 present when it died, determine the age of the fossil? Half life of Carbon-14 is 5700 years. (b)How much Carbon-14 will be present in the sample

75. ## Intermediate Maths

(a)-A fossilised tree was tested and contains 10 grams of Carbon-14. Given that there was 12 grams of Carbon-14 present when it died, determine the age of the fossil? Half life of Carbon-14 is 5700 years. (b)How much Carbon-14 will be present in the sample

76. ## physics

You are at a archeological dig an discover a strange artifact. It is a utinsil tha appears to be carved out of an elephant's tusk You analyze it and discover that it has 0.625 the amount of carbon -14 you woul find in a living specimen. How many half lives

77. ## Final Maths

(a)-A fossilised tree was tested and contains 10 grams of Carbon-14. Given that there was 12 grams of Carbon-14 present when it died, determine the age of the fossil? Half life of Carbon-14 is 5700 years. (b)How much Carbon-14 will be present in the sample

78. ## Math

If current trends of burning fossil fuels and deforestation continue, then future amounts of atmospheric carbon dioxide in parts per million (ppm) will increase exponentially. In the year of 1990, there was 353 ppm. A)In the year of 2000, there was 375 ppm

79. ## pre calc

You have a sample of a certain radioactive substance. After two days, thirty percent of the sample has decayed. What is the half-life of the material and how much will have decayed after a week?

80. ## pre calc

You have a sample of a certain radioactive substance. After two days, thirty percent of the sample has decayed. What is the half-life of the material and how much will have decayed after a week?

81. ## Biology

The half -life of carbon-14 is 5,730 years.how much of an initial amount of this substance would remain after 17,190 years(3 Half-lifes

82. ## science

The half-life of carbon-14 is 5730 years. If we start with 10 grams of carbon-14, after 5730 years, we will have _____ of carbon-14 left.

83. ## Physics - Half Life Question Check!!!

An ancient rock is found to contain 40Ar gas, indicating that 77% of the 40K in the rock has decayed since the rock solidified. Any argon would have boiled out of liquid rock. How long ago did the rock solidify? The half-life of 40K is 1.25 billion years.

84. ## chemistry

How do carbon-12 and carbon-13 differ? (select all that apply) they have different amount of electrons they have different amount of neutrons they have different atomic charges they have different mass numbers I know one of them is b please help

85. ## Math

An Anthropologist finds bones that her Instruments measure it as 0.921% of the amount of carbon- 14 the bones would have contained when the person was alive. How long ago did the person die? The half life, t 1/2, carbon 14 is 5,730 years. Round To the

86. ## Chemistry

An artifact has a carbon-14 to carbon-12 ratio that is one-fourth the carbon-14 to carbon-12 ratio of a similar modern object. How old is the artifact? (The half-life of carbon-14 is 5,715 years.)

87. ## Chemistry

A radioactive sample contains 3.25 1018 atoms of a nuclide that decays at a rate of 3.4 1013 disintegrations per 26 min. (a) What percentage of the nuclide will have decayed after 159 d? % (b) How many atoms of the nuclide will remain in the sample? atoms

88. ## Chemistry

The amount of solar radiation received anually in arizona is about 8.4 x 10^6 KJ/m^2. What mass of carbon must be burned into carbon dioxide to produce the same amount of energu in the following reaction? C + 02 --->CO2 deltaH=-393.5Kj

89. ## physics

The half-life of carbon-14 is 5730 years. How much of a 50 g sample of carbon-14 is present after 11,460 years?

90. ## Biology

The half-life of carbon-14 is 5,700 years. If a sample originally had 26 g of carbon-14, how much would it contain after 22,800 years?

91. ## Chemistry

A piece of wood found in an ancient city has a carbon-14 to carbon-12 ratio that is one-eighth the carbon-14 to carbon-12 ratio of a tree growing nearby. How old is the piece of wood? (The half-life of carbon-14 is 5,715 years.)

92. ## Earth Science

1. We start with 400 atoms of Uranium-238. How many remain after 4.5 billion years? _______ After 9 billion years? _______ After 13.5 billion years? ________ 2 . How long will it take for ½ of the original amount of Rubidium-87 to decay? _______ 3.

93. ## math

A tree typically lives 20 years and Given the dimension of a tropical tree, calculate how much carbon they contain when they are alive. There are an average of 200 trees per acre in the rainforest. Calculate the amount of carbon released when 1 acre of

94. ## Biology

If the original amount of Carbon-14 is 142 kilograms, how much will the sample weight in 11,400 years?

95. ## math

Carbon 14 (14C) dating assumes that the carbon dioxide on Earth today has the same radioactive content as it did centuries ago. If this is true, the amount of 14C absorbed by a tree that grew several centuries ago should be the same as the amount of 14C

96. ## Chemistry

An ancient artifact is found to have a ratio of C-14 to C-12 that is 1/8th the ratio of C-14 to C-12 found in objects today. How old is the artifact of the half like of C-14 is 5715 years?

97. ## chemistry

If I have a sample from doing a half lfe lab with m&ms, not timed, just pulling out decayed or m&ms with rhe m on top, how do I calculate the half life using t1/2=(.693)/k formula. Do I have to do this 9 times as it took 9 trys to use up all the m&ms. I am

98. ## Chemistry

The isotope caesium-137, which has a half life of 30 years, is a product of neuclear power plants. How long will it take for the amount of this isotope in a sample of caesium to decay to one sixteenth of its original amount. Explain answer 30 years 1/2 60

99. ## Chemistry

What is the famous isotope used in archeological dating? carbon 12 I thought it was carbon 14 yes carbon 14-- made an error But if you knew, why are you asking these questions? I need reaasurance, so when I have a test I know the exact answer C-14 is ONE

100. ## Math

The quantity Q of radioactive carbon remaining in a 300 - gram wood sample at time t is given by the expression Q(t) = 300 e^{- 0.000324*t}. How much radioactive carbon remains in the sample after (a) 200 years, (b) 50000 years, (c) 125500 years?