Friday

February 27, 2015

February 27, 2015

Number of results: 25,211

**College Algebra**

Carbon-14 Dating. Only 10% of the carbon-14 in a samll wooden bowl remains. How old is the bowl? Half life of carbon is 5700 years.
*December 8, 2010 by Vince*

**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?
*May 16, 2011 by Jennifer*

**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 each page contain ...
*April 3, 2012 by Anonymous*

**Intro to Astronomy**

The half-life of carbon 14, which is commonly used to date organic materials, is 5700 years. What is the minimum age of sample in which less than 1% of the organic carbon 14 is left?
*February 9, 2012 by M.T.*

**Calc II**

Carbon-14 has a half-life of 5700 years. The charcoal from a tree killed in the volcanic eruption that formed Crater Lake in Oregon contained 59.5% of the carbon-14 found in living matter. Approximate the age of Crater Lake.
*April 7, 2010 by Sarah*

**Chemistry**

The half-life of C-14 is 5700 years. If it took seven half lives for a sample of C-14 to decay completely, how many years would have gone by?
*January 24, 2013 by Mari*

**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?
*October 9, 2013 by becky*

**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 a time capsule how ...
*December 9, 2007 by Andy*

**half-life**

ok so i got... the half life of carbon-14 is 5730 years, the relation c+(1/2)^ N/5730 is used to calc. the concentration, c, in parts per trillion remaining n years after death determine the carbon concentration in a 11460 year old bone. please help :)
*June 30, 2010 by bubb*

**half-life**

ok so i got... the half life of carbon-14 is 5730 years, the relation c+(1/2)^ N/5730 is used to calc. the concentration, c, in parts per trillion remaining n years after death determine the carbon concentration in a 11460 year old bone. please help :)
*June 30, 2010 by bubb*

**Chemistry**

Uranium-238 has half life of 4.51 * 10^9 years Uranium-234 has half life of 2.48 * 10^5 years Thorium-230 has half life of 8.0 * 10^4 years Radium-226 has half life of 1.62 * 10^3 years Lead-210 has half life of 20.4 years. The rate constant for the decay of unstable nuclide X...
*March 20, 2012 by Harry*

**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.)
*March 17, 2013 by buffy*

**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.)
*June 6, 2013 by ro*

**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).
*May 5, 2014 by Kim Johnson*

**Alegbra**

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.
*May 10, 2014 by Mary Ann*

**alegbra**

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
*May 11, 2014 by gary*

**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
*July 15, 2011 by Lee Ann*

**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.
*July 17, 2011 by Anonymous*

**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.
*July 23, 2011 by Brandi*

**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.
*July 27, 2011 by can some please help me with this one*

**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
*October 20, 2011 by Anonymous*

**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.
*October 30, 2011 by suzie*

**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.
*January 22, 2012 by Anonymous*

**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.
*February 18, 2012 by Anonymous*

**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.
*November 3, 2012 by Anonymous*

**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.
*November 3, 2012 by Anonymous*

**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.)
*May 13, 2014 by Nellie*

**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 remains, so the ...
*April 7, 2014 by Taylor*

**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.
*April 16, 2012 by Yvonne*

**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.
*June 17, 2012 by Randy*

**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
*October 27, 2012 by Anonymous*

**physical science**

a scientist found a fossilized bison. using Carbon-14 dating, she found that the fossil was about 45,840 years old. Carbon-14 has a half-life of 5730 years. how many half-lives have passed?
*February 17, 2013 by sue moore*

**ChemB**

The activity of carbon 14 in living tissue is 15.3 disintegrations per minute per gram of carbon. The limit for reliable determination of age is based on carbon 14 is .10 disintegration per min per gram of carbon. Calculate the max age of a sample that can be dated accurately ...
*January 23, 2012 by L.Bianchessi*

**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?
*February 24, 2015 by Kareem*

**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?
*November 19, 2013 by Emily*

**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.)
*July 22, 2013 by John*

**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
*November 23, 2010 by Eileen*

**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.)
*July 22, 2013 by John*

**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 year. a. about 34,400 years b. ...
*April 25, 2011 by Eddy*

**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 year. a. about 34,400 years b. ...
*April 25, 2011 by Eddy*

**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 of the radioactive ...
*October 15, 2006 by Schooler*

**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.
*December 9, 2012 by Melissa*

**Math - D.E.Q.**

The half-life of a radioactive isotope is the amount of time it takes for a quantity of radioactive material to decay to one-half of its original amount. i) The half-life of Carbon 14 (C-14) is 5230 years. Determine the decay-rate parameter for C − 14.
*January 18, 2011 by Justin*

**Alg2**

A piece of wood discovered in an archaeological dig was found to have lost 62% of it's carbon-14. Carbon-14 has a half-life of 5630 years. Determine it's age.
*June 1, 2010 by Cal*

**Chem 2 help**

what is the significance of calculating the half life of a reaction? How has the concept of half-life been used to develop the method of carbon dating? If a substance does not contain the element carbon can the method of carbon dating be used to date the artifact? Thanks!
*November 11, 2014 by anonymous.*

**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 absorbs carbon dioxide ...
*March 7, 2013 by Emily*

**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 carbon 14 it contained ...
*March 17, 2014 by Andy G*

**science**

Carbon-14 has a half-life of approximately 5,730 years. How many half-lives have occurred in a sample that contains 50 percent of the original amount of the parent isotope?
*July 2, 2012 by ticie burke*

**Calculus**

A fragment of bone is discovered to contain 20% of the usual carbon-14 concentration. Estimate the age of the bone to the nearest hundred years, given that Carbon-1 is radioactive with half-life of 5730 years and the rate of decay is given by the following differential ...
*May 21, 2014 by Kristin*

**College Algebra**

Only 34% of the carbon-14 in a wooden bowl remains. How old is the bowl? (Carbon-14 has a half-life of 5,700 years.)
*November 22, 2010 by Lexi*

**College Algebra**

Only 27% of the carbon-14 in a wooden bowl remains. How old is the bowl? (Carbon-14 has a half-life of 5,700 years.)
*December 1, 2010 by Laura Hieb*

**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?
*April 24, 2012 by Mima*

**math**

only 5% of the carbon-14 in a small wooden bowl remains , how old is the bowl? Hint, half-life for carbon –14 us 5730 years
*April 4, 2012 by martha*

**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?
*November 20, 2010 by Hannah*

**ChemB**

measurements of carbon 14 taken from linen wrappings of the book of isaiah from the dead sea scrolls indicate that the scrolls contain 79.5% of the carbon 14 expected in living tissue. how old are these scrolls if the half life of carbon 14 is 5730 years? All radioactive decay...
*January 22, 2012 by L.Bianchessi*

**Precalculus**

The burial cloth of an Egyptian mummy is estimated to contain 57% of the carbon-14 it contained originally. How long ago was the mummy buried? (The half-life of carbon-14 is 5730 years.)
*June 10, 2010 by Miguel*

**Precalculus**

The burial cloth of an Egyptian mummy is estimated to contain 57% of the carbon-14 it contained originally. How long ago was the mummy buried? (The half-life of carbon-14 is 5730 years.)
*June 10, 2010 by Miguel*

**Chemistry**

Which radioactive sample would contain the greatest remaining mass of the radioactive isotope after 10 years? A. 2.0 grams of 198 Au B. 2.0 grams of 42 K C. 4.0 grams of 32 P D. 4.0 grams of 60 Co By the way the numbers next to the elements are their atomic masses. thanks ...
*March 3, 2007 by Sanjay*

**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.
*May 22, 2014 by kim*

**earth science**

what would be the chart to use for carbon 14 whcih has a half life of 5730 years and a piece of wood which originally has 12 grams pf radioactive isotope; If the half lives occurred and now has 0.75 grams left?
*November 29, 2012 by lan*

**Chemistry **

If 100.0 g of carbon-14 decays until only 25.0 g of carbon is left after 11,460 y, what is the half-life of carbon-14?
*December 11, 2012 by Jacob *

**chemistry**

A wooden object from a prehistoric site has a carbon-14 activity of 10 counts per min.(cpm) compared to 40 cpm for new wood. If carbon-14 has a half life of 5730 years what is the age of the wood? Please get me started. Thank you
*October 19, 2011 by Connie*

**science **

The half-life of carbon 14 is 5730 years. if a 1 g sample of old carbon is 1/8 as radioactive as 1 g of a current sample, then the age of the old sample is about ___________years. 22,900 17,200 11,500 716
*March 5, 2012 by chuck *

**chemstry**

How long will it take 200 mg of carbon-14 to decay to the point where only 75 mg remain if the half-life is 5770 years?
*October 31, 2013 by jordan*

**chemstry**

How long will it take 200 mg of carbon-14 to decay to the point where only 75 mg remain if the half-life is 5770 years?
*October 31, 2013 by jordan*

**science**

how old is a mammoth's tusk if there is only 25 percent C-14 remaining in the sample? a.5700 years b.11400 years c.17100 years d.22800 years
*April 4, 2009 by Angie*

**Science **

Carbon-14 has a half-life of about 5,600 years. Archaeologists analyze a piece of wood found at an ancient village site and determine that, of he initial 100 grams of Carbon-14 in the wood, onl 3.125 grams are left. How old is the wood?
*August 13, 2011 by Nicole*

**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 disintegrations/ min per...
*December 5, 2014 by Rachel*

**math**

1.The remains of an old campﬁre are unearthed and it is found that there is only 80% as much radioactive carbon-14 in the charcoal samples from the campﬁre as there is in modern living trees. If the half-life of carbon- 14 is 5730 years, how long ago did the camp...
*November 12, 2013 by hannah*

**half life**

tritium has a half life of 24.3 years .a sample of 0.1 is produced . will tthe mass of tritium change after 24.3 years
*April 14, 2011 by Anonymous*

**physics**

If the physical half-life of sulfur-35 is 87.1 days, and the biologic half-life in the testicle is 632 days, what is its effective half-life in this organ? I know i have to find the time and then the half-life. But im having trouble finding the time A(t)=Ao x e ^ (-0.693) (t...
*October 24, 2013 by Sarah*

**Science**

Choose the explanation that does the following: (1) identifies the element used in carbon dating and (2) explains why the element is used. A. iodine-131; iodine is present in the thyroid glands, is radioactive, and has a very long half-life B. nitrogen-14; radioactive carbon ...
*September 26, 2014 by Anonymous*

**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, determine the age of ...
*February 16, 2007 by soojung*

**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 this known piece of ...
*July 24, 2009 by j*

**Algebra 2**

half life carbon -14 is 5,730 years. If you start out 50 grams, how long will it take until it reaches 2 grams?
*May 20, 2012 by chels*

**Math**

The half-life of carbon-14, which is used in dating archaeological finds, is 5730 yr. Assume that 100% of the carbon-14 is present at time 0 yr, or x=0. Write the equation that expresses the percentage of carbon-14 remaining as a function of time.
*October 11, 2011 by Hanna*

**chemistry**

Radioactive waste is difficult to dispose of due to the long time periods needed before the radiation effectively disappears. The US protocol is to store the waste for 10 half-lives of the material after which the waste is no longer considered radioactive. After this time, ...
*February 14, 2015 by danny*

**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
*September 24, 2012 by Shay*

**Physicr**

A 10 kg sample from a living plant has actiuity 30 000 Bq due to Carbon-14. A 500g sample of the same type of plant but dead has activity 1 000 Bq. Calculate the age of the dead sample given that the half life of Carbon-14 is 5568 years
*October 14, 2013 by Culvin*

**chemistry**

The isotype 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 isotype in a sample of caesium to decay to one-sixteenth of its original amount? first half life 1/2 second 1/4 third 1/8 fourth 1/16...
*March 6, 2007 by Charley*

**chem**

Can someone please help me with the following questions? 1:Suppose you were given an ancient wooden box. If you analyze the box for carbon-14 activity and find that it is 50% of that of a new piece of wood of the same size, how old is the wood in the box? 2:How old is an ...
*January 2, 2007 by Margaret*

**Chemistry**

Carbon-14 has a half-life of 5730 y. How much of a 144 g sample of a carbon-14 will remain after 1.719 (times) 10 4y?
*December 11, 2012 by David*

**Chemistry**

Carbon-14 has a half-life of 5730 y. How much of a 144 g sample of a carbon-14 will remain after 1.719 (times) 10 4y?
*December 11, 2012 by David*

**Math **

Suppose a quantity is halvd every 18 years. use the approximate half-life formula to estimate its decay rate. is the half life equation y= 1/2^t1/2 2^1/2t= 1/y t 1/2= log2 (1/y) Where do I put 18 at?
*December 4, 2009 by Randi*

**chemistry**

90Sr is one of the harmful radionuclides resulting from nuclear fission explosions. It decays by a first-order process with a half-life of 28 years. How many years would it take for 99.99% of a given sample released in the atmosphere to disintegrate? Answer in units of years. ...
*April 29, 2010 by omar*

**Algebra**

In 10 years, 25% of a radioactive substance decays. What is its half-life? A. 25 years B. 24 years C. 20 years D. 29 years
*December 12, 2012 by Darwin12*

**Math**

In 10 years, 25% of a radioactive substance decays. What is its half-life? A. 25 years B. 24 years C. 20 years D. 29 years
*December 14, 2012 by Darwin12*

**Calculus**

Skeletal remains had lost 81% of the C-14 they originally contained. Determine the approximate age of the bones. (Assume the half life of carbon-14 is 5730 years. Round your answer to the nearest whole number.) yr
*July 12, 2013 by Anonymous*

**calculus**

Skeletal remains had lost 70% of the C-14 they originally contained. Determine the approximate age of the bones. (Assume the half life of carbon-14 is 5730 years. Round your answer to the nearest whole number.)
*March 2, 2014 by angie*

**Math**

Skeletal remains had lost 84% of the C-14 they originally contained. Determine the approximate age of the bones. (Assume the half life of carbon-14 is 5730 years. Round your answer to the nearest whole number.)
*April 5, 2014 by Vanessa*

**math**

How long will it take a given quantity of carbon-14 to lose 99.9% of its radioactivity if the half life is 5730 years? The formula I have been given is Q=ae^rt This is using log and ln functions.
*April 25, 2011 by Niki*

**math**

one fifth of my life I wanted to become a teacher. 3/25 of my life I was a teenager. 9/25 of my life I was married to my husband. Three-fifth of my life my son was born. Fifteen years after that, my daughter was born. Seven years after that I got a divorce from my husband. ...
*March 9, 2011 by ann*

**Chem 3A**

please help me with this chemistry problem. Half-Life A radium-226 sample initially contains 0.112 mol. How much radium-226 is left in the sample after 6400 years? The half-life of radium-226 is 1600 years.
*July 5, 2008 by shylo*

**Chemistry**

A sample of charcoal is found to have only 1/8th of Carbon-14. Half-life of Carbon-14 is 5730yrs, what is the age of the charcoal?
*December 1, 2012 by Anonymous*

**Exponential Decay**

the half-life of carbon-11 is 20 minutes. How long will it btake for 600g of carbon-11 to decay to 30g?
*October 22, 2009 by Mark*

**math**

I have to write an equation for the following. The daily newspaper started printing three years ago they had 5700 home delivery subscribers. The number of subscribers increased by 67 every month. write equation that shows the relationship between number od subscribers B and ...
*January 17, 2010 by jess*

**Calculus**

The half life of a certain radioactive substance is 10 years. How long will it take for 18 gms of the substance to decay to 6 gms? A. 6 ln 10 years B. 10 ln 6 years C. 10 (ln 3)/(ln 6) years D. 18 ln 10 years E. 10 (ln 3)/(ln 2) years
*January 27, 2013 by Anonymous*

**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 carbon-14 decay, 5715 yr, ...
*May 1, 2011 by Anonymous*

**Half-Life**

Uranium-238 decays to Lead-206. The half life of Uranium-238 is 4.5 billion years. If you have a 100 g sample. How much sample will you have after 2 half lifes?
*February 19, 2012 by Noah*

**physics**

If an archaeologist finds an ancient fire pit containing partially consumed firewood and the 14C content of the wood is only 10% of an equal carbon sample from present day tree, what is the age of ancient site. 14 C has half life of 5730 years
*May 4, 2014 by Dave*

Pages: **1** | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | Next>>