Tuesday

March 31, 2015

March 31, 2015

Posted by **Sandhya** on Saturday, April 19, 2008 at 2:09pm.

2) A specimen taken from the wrappings of a mummy contains 7.02 g of carbon and has an activity of 1.34 Bq. How old is the mummy? Determine its age in years assuming that in living trees the ratio of 14C/12C atoms is 1.23E-12.

Please check my answers

1)

For 14 C T 1/2 = 5570 years N/N0 = 11.9/100 = 0.119

N / N0 = e- λ t 2.303 x In 0.119 = -λt λ =0.6931 / 5570 =1.244 x 10 -4

t = (2.303 x In0.119 x 5570) / 0.6931 = 17110 years

2)

R = 1.34 Bq = 1.34 decays / second

14 C atoms / 12 C atoms = 1.23 x 10-12 = N0/N N/N0 = 10 12 /1.2

Number of atoms contained in 7.02 g of carbon

= (7.02 x 6.023 x 10 23) /14 = 3.02 x 10 23 N = 3.02 x 10 23

R = Nλ λ = 1.34 / 3.02 x 10 23 = 0.4437 x 10 -23

2.303 x In (10 12 /1.23 ) = -0. 4437 x 10 -23 x t

t = 61.82 x 10 23 seconds = 1.96 x 10 17 years

- Physics -
**Sushma**, Wednesday, December 17, 2008 at 12:41pmT 1/2 of C14=5730 yrs.

Here is the answer for the 1st one, hope it will be helpfull.

Lamda= ln2/(T1/2)

= 0.693/5730=1.209E-4

N/N0= 11.9/100 = 0.119

N=N0 e^-lamda*t

N/N0=e^lamda*t

ln(0.119)= 1.209E-4t

t=ln(0.119)/(1.209E-4)

t=17606.5 yrs.

- Physics -
**Sushma Rai**, Wednesday, December 17, 2008 at 12:46pmT 1/2 of C14=5730 yrs.

Here is the answer for the 1st one, hope it will be helpfull.

Lamda= ln2/(T1/2)

= 0.693/5730=1.209E-4

N/N0= 11.9/100 = 0.119

N=N0 e^-lamda*t

N/N0=e^lamda*t

ln(0.119)= 1.209E-4t

t=ln(0.119)/(1.209E-4)

t=17606.5 yrs.

(ps: this is also for my Montgomery College, Takoma Park college Dr. Shaleen Shukla PH 204 class)

**Answer this Question**

**Related Questions**

Nuclear physics - 1) An old wooden tool is found to contain only 11.9 percent of...

Nuclear physics Repost - 1) An old wooden tool is found to contain only 11.9 ...

chemistry - Archeologists can determine the age of artifacts made of wood or ...

chemistry/math - 100g of bone contain ratio of 14C and 12C. 6.8% 14C is present ...

Chemistry - The half-life for radioactive decay of 14C is 5730 years (it emits...

physicsRadioactivity - A specimen taken from the wrappings of a mummy contains 7...

Chemistry - A skull fragment found in 1936 at Baldwin Hills, California, was ...

Physics - An astronaut is taking a space walk near the shuttle when her safety ...

Radioactivity - 1. A granite rock is thought to be about 2 billion years old. ...

Physics - A specimen has .625 the amount of carbon 14 you would find in a living...