Element x Isotope 55x 60% Isotope 56x 30% Isotope. 57x 10% 55× 60 =3300 56×30=1650 57× 10= 570 Add them up5520 divide by 100 the atomic weight of x is 55.2 Pls check if this is correct , answer and
3,167 results
Chemistry
On another planet, the isotopes of titanium have the following natural abundances. Isotope 46Ti Abundance 70.900% Mass(amu) 45.95263 Isotope 48Ti Abundance 10.000% Mass(amu) 47.94795 Isotope 50Ti Abundance 19.100% Mass(amu) 49.94479 What is the average

Differential Equations
Model radioactive decay using the notation t = time (independent variable) r(t) = amount of particular radioactive isotope present at time t (dependent variable) λ = decay rate (parameter) Note that the minus sign is used so that λ > 0 a) Using this

Chemistry
A SAMPLE OF ANTIMONY, Ar=121.8, WAS ANALYSED AND WAS FOUND TO CONSIST OF 60% OF 121Sb AND ONE OTHER ISOTOPE. DETERMINE THE MASS NUMBER OF THE OTHER ISOTOPE IN THE SAMPLE OF ANTIMONY. please help I'm really stuck,

math
Complete the table for the radioactive isotope. (Round your answer to two decimal places.) Isotope: 239Pu Halflife (years): 24,100 Initial Quantity: g Amount After 1000 Years: 0.6

Chemistry
A fictitious element X is composed of 10.0 percent of the isotope 55^X , 20.0 percent of the isotope 56^X , and 70.0 percent of the isotope 57^X . Calculate the weighted atomic mass of element X to the nearest tenth.

Chemistry
write isotpoic symbols of the form XA (for example, C13) for each of the following isotopes. **Do I add the number of protons and neutrons together to get the answer? The symbol is easy to figure out.** a) the iodine isotope with 74 neutrons B) the

Chemistry
1. A hypothetical pure element consists entirely of two isotopes. The natural percent abundance of the isotope with mass 25.5 u is 86.1%. The other isotope has mass 29.2 u. Calculate the atomic weight of the naturally occurring element. 2. Suppose that a

chemistry
One isotope of a nonmetallic element has mass number 16 and 7 neutrons in the nucleus. The anion derived from the isotope has 10 electrons. Write the symbol for this anion. I thought the answer was O^2 but this isnt correct

Chemistry
Cobalt60 is a radioactive isotope used to treat cancers. A gamma ray emitted by this isotope has an energy of 1.33 MeV (million electron volts; 1 eV = 1.602 multiplied by 1019 J). What is the frequency (in Hz) and the wavelength (in m) of this gamma ray?

Chemistry/Physics
"Colbalt60 is a radioactive isotope used to treat cancers of the brain and other tissues. A gamma ray emitted by an atom of this isotope has an energy of 1.33 MeV (million electron volts; 1 eV = 1.602*10^19 J). What is the frequency (in Hz) and

chem
Consider the isotope arsenic76 How many protons are in an atom of this isotope? 33 What is the mass number of this isotope? 76 How many neutrons are in an atom of this isotope? 43 What is the atomic number of this isotope? 33 Give the nuclear symol 76/33

Chemistry
Gallium65, a radioactive isotope of gallium, decays by first orderkinetics. The halflife of this isotope is 15.2 min. How long would it take for 7/8 of a sample of this isotope to decay? 15.2 min 30.4 min 45.6 min 48.0 min I'm not sure how to do this. I

MATH help
a certain radioactive isotope has a half life of approx 1,300 years . How many years to the nearest year would be required for a given amount of this isotope to decay to 55% of that amount. So I am not sure where to put the 1,300 1,300=2600*e^t or

Calculus
The rate of decay is proportional to the mass for radioactive material. For a certain radioactive isotope, this rate of decay is given by the differential equation dm/dt = .022m, where m is the mass of the isotope in mg and t is the time in years. A. If

chemistry
one isotope of chromium (atomic number 24) has an atomic mass of 53 amu. how many neutrons are in this particular isotope of chromium? A. 24 B. 29 C. 53 D. 77 I say A

chemistry
One isotope of a metallic element has mass number 59 and 31 neutrons in the nucleus. The cation derived from the isotope has 26 electrons. Write the symbol for this cation.

Algebra
Two different radioactive isotopes decay to 10% of their respective original amounts. Isotope A does this is 33 days, while isotope B does this in 43 days. What is the approximate difference in the halflives of the isotopes? 3 days 10 days 13 days 33 days

math
3. Write the exponential growth function to model the following situation: A population of 422, 000 increases by 12% each year. 4. At t = 0 there are 50 grams of a radioactive isotope. The isotope has a halflife of 16 minutes. Use the exponential decay

Math
An isotope of sodium has a halflife of 20 hours. Suppose an initial sample of this isotope has mass 10 grams. The amount of the isotope (in grams) remaining after t hours is given by: (Note: We're assuming exponential decay here. Use the exponential decay

astronomy
The isotope potassium40 (40K) decays into the isotope argon40 (40Ar) with a halflife of 1.25 billion years. Suppose we find a rock in which seveneighths of the potassium40 has decayed to become argon40, and only oneeighth of the original

Chemistry
An element consists of 1.40% of an isotope with mass 203.973 amu, 24.10% of an isotope with mass 205.9745 amu, 22.10% of an isotope with mass 207.9766 amu. Calculate the average atomic mass and identify the element

college
a certain radioactive isotope has a half life or 850 years.how many years would it take for a given amount of this isotope to decay to 70% of that amount?

mathematics
The exponential formula for the halflife of a radioactive isotope is y=y0ekt, where y is the amount of the isotope remaining after t years, y0 is the initial amount of the isotope, k is the decay constant, and e is the transcendental number approximately

Chemistry
An isotope, X, of a particular element has an atomic number of 15 and a mass number of 31. Which of the following statements are true? I. X is an isotope of phosphorus. II. X has 16 neutrons per atom. III. X has an atomic mass of 30.973

physics
The halflife of the plutonium isotope is 24,360 years. If 10 grams of plotonium is released into the atmosphere by a nuclear accident, how many years will it take for 80% of the isotope to decay?

Math help
Gold (Au) has a synthetic isotope that is relatively unstable. After 25.5 minutes, a 128gram sample has decayed to 2 g. What is the halflife of this isotope? 8.5 minutes 2.25 minutes 1.5 minutes 4.25 minutes

Chemistry
I've figured out most of it. I'm not sure how to find the percentage ofd the isotope. Define the half life. The halflife of a radioisotope is found to be 4.55 minutes. If the decay follows first order kinetics, what percentage of isotope will remain after

chemistry ASAP
calculate the average atomic mass of element x in which the first isotope found in 28.5% abundance weighs 200.0 amu and the other isotope weighs 220.0 amu.

Chemistry
How to solve this: One isotope of a metallic element has mass # of 65 and 35 neutrons in nucleus. The cation derived from the isotope has 28 electrons. Write the symbol for this cation. Would the symbol be Cu? because Atomic # = protons = electrons and

Radioactivity or science
A radioactive isotope source has a mass of 120ug. If the isotope had a half life of 20s, what would be the mass if the isotope after 2 mins?

Calculus
My teacher wants me to use this formula for half life question C(t) = Ce^kt but i used a different formula plz help. the question is: A radioactive isotope has a half life of 30 years. If we started off with 10 mg of this isotope 12 years ago: a) Find and

chem
one isotope of carbon has the atomic # 6+ the mass #14. An Atom of this isotope contain how many elctrons

Science chemistry
It takes 1 hour and 17 min. for a 1.000gsample of a certain isotope to decay to 0.121g. What is the halflife of this isotope? plssss helpp

Isotopes
I have an isotope, 292 uuh 116 this suffers seven successive alpha decay reactions, I know each for alpha decay reaction the isotope loses 4 He 2 so the atomic weight decreases by four, and the atomic number by 2... None of the elements shown in the

physics
in an initial mass of 40g, how much mass Remaining of the Isotope Approximately how much mass remains after 8.0 hours? After 21 hours, and what is the half life of the isotope

Chemistry
The isotope caesium137, 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

Chemistry
When is an isotope considered stable? _(Select all that apply.)_ The isotope does not emit a form of radiation. The isotope’s halflife is longer than the average human life. The isotope emits some form of radiation. The isotope’s halflife is too long

Chemistry
A hypothetical pure element consists entirely of two isotopes. The natural percent abundance of the isotope with mass 25.5 u is 78.8 percent. The other isotope has mass 29.5 u. Calculate the atomic weight of the naturally occurring element.

chemistry ASAP
calculate the average atomic mass of element x in which the first isotope found in 28.5% abundance weighs 200.0 amu and the other isotope weighs 220.0 amu.

math
A 10 kg quantity of a radioactive isotope decays to 3 kg after 17 years. Find the decay constant of the isotope.

math
A 10 kg quantity of a radioactive isotope decays to 3 kg after 17 years. Find the decay constant of the isotope.

chemistry
It takes 1 hour and 17 min. for a 1.000g sample of a certain isotope to decay to 0.121g. What is the halflife of this isotope? plssss helpp

chemistry
A radioactive isotope of radium (Ra226) has a halflive of 1620 years. How much of this isotope remains after three (3) halflives? A. 1/2 B. 1/4 C. 1/8 D. None would this be C? please explain, thank you!

chemistry
A radioactive sample contains 2.45g of an isotope wiht a half life of 3.8 days. How much of the isotope in grams remains after 11.4 days? please explain

Physics check
A certain radioactive isotope has a halflife of one hour. At noon, 100g of the material is present. How much of the original isotope will be present at 3:00 p.m.1/8 6:00 p.m.1/16 10:00 p.m.1/32 Are these correct?

Chemistry
If a 100.0 gram sample of a radioactive isotope goes through three halflives, how much of the original radioactive isotope will remain?

Chemistry
The strontium90 isotope decays by the reaction below. It has a halflife of 28 yr. If the initial activity of this isotope was 168dpm, what would the activity be after 28.0 yr?

chemistry
Cobalt60 is radioactive isotope used to treat cancers. A gamma ray photon emitted by this isotope has an energy of 2.13 x 10—13 J. What is the wavelength of this gamma ray in SI unit?

Calculus
A radioactive isotope has a half life of 25 years. There was 100 mg of the isotope in 2005. (a) Find an expression for the amount of the isotope, A(t), that is still active using time t, measured in years since 2005. Your expression must be of the form

Science
If an unstable isotope contained 5 protons and 8 neutrons, how many neutrons would need to decay to make the unstable isotope stable?

Earth Science
If an unstable isotope contained 5 protons and 8 neutrons, how many neutrons would need to decay to make the unstable isotope stable? Please Help!

chemistry
Element x Isotope 55x 60% Isotope 56x 30% Isotope. 57x 10% 55× 60 =3300 56×30=1650 57× 10= 570 Add them up5520 divide by 100 the atomic weight of x is 55.2 Pls check if this is correct , answer and method

Chemistry
Element X has three isotopes Isotope 1 Isotope 2 Isotope 3 Mass 28 29 30 Abundance % 92.18 4.71 3.12 ii)Use the isotope abundances and masses to calculate the relative atomic mass of x. Quote your answer to one decimal place. ii) Identify Element X. Show

Chemistry
A fictitious element X is composed of 78.0% of the isotope X50, 15.0% of the isotope X51 , and 7.0% of the isotope X52. Estimate the atomic mass of element X. Show your work.

chemistry
A fictitious element X is composed of 70.0 percent of the isotope X^45, 20.0 percent of the isotope X^ 46, and 10.0 percent of the isotope X^47. Calculate the weighted atomic mass of element X to the nearest tenth. pls show all work

Chemistry
1.)Two different Isotopes are found to have 2 different cpm with Isotope A having a CPM that is 1.5x that of Isotope B? Which one is more radioactive? 2.) And how can CPM for an isotope be increased? I think that for the same CPM you can have different

Radioactivity
How are the terms "activity" and "becquerel" related? A radioactive isotope source has a mass of 120 g. If the isotope has a half life of 20 secs what would be the mass of the isotope in 2 mins?

chemistry
A hypothetical pure element consists entirely of two isotopes. The natural percent abun dance of the isotope with mass 25.6 u is 47.2%. The other isotope has mass 29.7 u. Calculate the atomic weight of the naturally occurring element.

Chemistry
Element L has an average atomic mass of 54.2488 amu and is composed of two isotopes. The first has a mass of 55.2036 amu and makes up 41.030% of a standard sample. What is the mass of the second isotope? I under how to get average atomic mass but not sure

chemistry
the longest lived radioactive isotope yet discovered is the betaemitter tellurium130.it has been determinded that it would take 2.4 x 10^21 years for 99.9% of this isotope to decay. write the equation for this reaction, and identify the isotope into

Calculus
A radioactive isotope has a half life of 25 years. There was 100 mg of the isotope in 2005. (a) Find an expression for the amount of the isotope, A(t), that is still active using time t, measured in years since 2005. Your expression must be of the form

Physics 30
A radioactive isotope(h=4.5days) was prepared. This isotope was used 14 days later when it had an activity of 6000000 Bq. What was the activity of this isotope when initially prepared?

math
A 10 kg quantity of a radioactive isotope decays to 3 kg after 17 years. Find the decay constant of the isotope.

math
A 10 kg quantity of a radioactive isotope decays to 3 kg after 17 years. Find the decay constant of the isotope.

isd muscat
after two hours 1/16th of the radioactive isotope remains undecayed.half life of the isotope is

math
A 10 kg quantity of a radioactive isotope decays to 3 kg after 17 years. Find the decay constant of the isotope.

math
A 10 kg quantity of a radioactive isotope decays to 3 kg after 17 years. Find the decay constant of the isotope.

math
A 10 kg quantity of a radioactive isotope decays to 3 kg after 17 years. Find the decay constant of the isotope.

Chem
The decay constant for a radioactive isotope is 7.82 x 106 /y. What is the halflife of this isotope in years?

Halflife
After two hours, 1/16 of the initial amount of a radioactive isotope remains undecayed. What is the halflife of the isotope?

Phys Sci
determine the isotope produced in the beta decay of iodine131 an isotope used to check thyroid gland function

Physics
A certian radioactive isotope has a halflife of 1 hour. If you start with 1 gram of the material at noon, how much of the original isotope will the sample contain at 3 pm? At 6 pm? At 10 pm?

Chemistry
Consider that: the tetravalent cation of an isotope has 78 electrons and 128 neutrons; Nuclear relative mass of the same cation is 1.44% higher than the relative nuclear mass of its most common isotope based on these data, calculate the number of neutrons

Chemistry
Consider that: the tetravalent cation of an isotope has 78 electrons and 128 neutrons; Nuclear relative mass of the same cation is 1.44% higher than the relative nuclear mass of its most common isotope based on these data, calculate the number of neutrons

math, calculus
A radioactive isotope has a half life of 25 years. There was 100 mg of the isotope in 2005. (a) Find an expression for the amount of the isotope, A(t), that is still active using time t, measured in years since 2005. Your expression must be of the form

geo/science
could you please tell me if this is the correct formula for radiometric date t=1/constant 1n (1+d/p) many thanks ps this is a fantastic website I think that you are after t=1/ë[ln(1+D/P)] where: t = age of the sample D = number of atoms of the daughter

Chemistry
A sample of a curium isotope was roasted. It was determined that the product( curium oxide) contained 11,59% of oxygen.¿ What is the equivalent weight of the isotope in the oxide? ¿ What is the mass of the curium isotope? I have already gotten the answer

Calculus
A radioactive isotope has a half life of 25 years. There was 100 mg of the isotope in 2005. (a) Find an expression for the amount of the isotope, A(t), that is still active using time t, measured in years since 2005. Your expression must be of the form

Science
9. Assume you began with 10 g of a radioactive parent isotope. How many grams of parent isotope will be present in the same sample after 2 halflives? A. 5.0 g B. 2.5 g C. 1.25 g D. 0.63 g Is it A???

Chemistry(please check my answer)
A radioactive isotope of radium (Ra226) has a halflive of 1620 years. How much of this isotope remains after three (3) halflives? A. 1/2 B. 1/4 C. 1/8*** D. None

chemistry
A radioactive sample contains 2.45 g of an isotope with a halflife of 3.8 days. How much of the isotope in grams will remain after 11.4 days?

College Geology
assume that a particular radioactiveisotope has a halflife of 100 million years. Also assume that the parent isotope is incorporated into the minerals found in igneous rocks and that the only daughter atoms in the rock formed from the decay of the parent

science
1.Carbon14 is a radioactive isotope. What is an isotope? What is the approximate halflife of carbon14?

math
What is the figure that gives the halflife of the isotope in minutes to 4 significant figures? Exponential regression on a set of data, which gives the amount of atoms of a radioactive isotope remaining after a time X minutes, produced the following

chemistry
We have not even covered this material. Samples of 131I take 10 hours to prepare to ship. It takes 2 weeks to get to its destination. How much 131I must be produced to ensure the patient receives 8 grams of NaI using the 131I isotope in the compound? Does

statistics
I have tried for days to figure out how to work this problem. Please help show me how to find the answer. A particular radioactive isotope decays from 210 mg to 182.7 mg in 15 days. Find the half life of the isotope.

Biology
How do you determine how the age of a specimen where there is only 1/2 of the original Carbon14 isotope left? What if 1/2 of the original isotope was left? I cannot show my work because I do not know how to figure this out.

s103
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 amount?  explain answer 1/16 = 1/2^x

physics
Is copper (Cu) the same as copper64 (Cu64)? Cu64 is a radioactive isotope of copper. Its half life is 12.8 hours. During the few days it is around, it behaves chemically like any other copper isotope, but eventually it all turns into something else. The

Physics
1. A gold atom has a mass of 3.287 • 1025 kg and is at rest. It emits an alpha particle that has a mass of 6.646 • 1027 kg. In this process, the gold atom is transformed into an iridium isotope. The alpha particle has a speed of 3.40 • 106 m/s. A.

algebra
the isotope has a very short life of 13 halflife days. estimate the percentage of the original amount of the isotope released by the explosion that remains 3 days after the explosion?

Chemistry
If a radioactive isotope has a half life of 162 days how many half lives would it need to go through to have 50% of that isotope to be nonradioactive?

Alpha decay
Hi I am working on a question which discusses ununhexium atomic number 116 atom weight 292. This isotope undergoes 7 alpha decay reactions. I have calculated that after seven reactions the product would be 102 nobelium. I cannot understand how the atomic

science
what is the heaviest element that has only one isotope and is not radioactive?

chemistry
What is the heaviest element that has only one isotope and is not radioactive?

chem
The halflife of the Nobelium isotope No^257 is about 23 seconds. 644 seconds (or 28 halflife periods) after the isotope was released there were 20 grams remaining. The number of grans of No^257 after h half life periods is M= 20 * (1/2)^h where h = 0

modern physics
A radioisotope P has a halflife of 3 s. At t = 0, a given sample of this isotope contains 8000 atoms. Calculate (i) its decay constant, (ii) average life, (iii) the time t1 when 1000 atoms of the isotope P remain in the sample, and (iv) number of decays

MATH help
a certain radioactive isotope has a half life of approx 1,300 years . How many years to the nearest year would be required for a given amount of this isotope to decay to 55% of that amount. So I am not sure where to put the 1,300 1,300=2600*e^t or

Math
a certain radioactive isotope has a half life of approx 1,300 years . How many years to the nearest year would be required for a given amount of this isotope to decay to 55% of that amount. So I am not sure where to put the 1,300 1,300=2600*e^t or

MATH help
a certain radioactive isotope has a half life of approx 1,300 years . How many years to the nearest year would be required for a given amount of this isotope to decay to 55% of that amount. So I am not sure where to put the 1,300 1,300=2600*e^t or