The half-life of an element is 20 years. In how many years will there be 12.5% of the initial material remaining

Q: The half-life of strontium-90 is 28 years. How long will it take a 50-mg sample to decay to a mass…

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Q: If you are told the half life of a material is 3,500 years, then how much would be remaining from a…

A: Given data: Half life (t1/2)= 3,500 years Initial quantity of the substance (N0) = 10 g Time elapsed…

Q: The half-life of Carbon-14 is 7 years. How much of an initial 168 g sample will remain after 30…

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Q: Which of water, iron, ammonia, chromium, radon, and silicon are chemical compounds as opposed to…

A: We have to write the chemical compounds as opposed to elements

Q: The half life of Thorium is 75,000 years. How much of the substance will be left after 3 half lives

A: Let initial amount of substance is m. The half life is T= 75000 years.

Q: sample of iodine-126 with an original mass of 15mg loses 13.125mg of the original mass of the…

A: sample of iodine-126 with an original mass of 15mg loses 13.125mg of the original mass of the…

Q: 1 atomic mass unit is about:

A: One atomic mass unit is defined as a mass exactly equal to one – twelfth the mass of one carbon -12…

Q: How many protons are in the nucleus of an antimony atom

A: An atom mainly consists of two parts: nucleus and electron orbits. In the nucleus, there are two…

Q: Lithium has only two naturally occuring isotopes: lithiumi-6 and lithium-7.  Lithium-6 has a mass of…

A: The atomic mass of lithium can be determined by the following expression.

Q: A mine worker discovers an ore sample containing 500 mg of radioactive material. It was discovered…

A: Given data: Mass of radioactive material, mo=500 mg Number of half-life, n=7 Applying the formula:…

Q: The half-life of radium-226 is 1600 years. How long will it take for 10.0 mg of radium-226 to decay…

A: Using half life concept to solve the problem

Q: A particular isotope has a half-life of 1 minute. If you start with 1 gram of this isotope, how much…

A: In the given question, We have to determine the remaining quantity of the isotope after 10 minute.

Q: One half-life of an isotope is 22 years. How many years would it take to have only 25% of the…

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Q: Cobalt-60 has a half-life of approximately 5 years. If 53g of the material was stored for 20 yers,…

A: mi=m0×2nmi: initial mass=53 kgm0=remaining mass n= number of periods

Q: If carbon-14 has a half life of 5,730 years and a sample contains 50 moles originally, how much is…

A: You have posted more than one non related questions. As per our policy first question will be…

Q: Phosphorus-32 is a commonly used radioactive nuclide in biochemical research, particularly in…

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Q: In the fall of 2002, scientists at Los Alamos National Laboratory determined that the critical mass…

A: The expression for find volume of the sphere is V=mρ Substitute values in the above equation…

Q: A radioactive material has a half-life of eight days. How long will it take for the material to be…

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Q: What is the most abundant element in the known universe?

A: There are 114 known elements in the universe.

Q: A human skeleton found at an archeological site is found to have on 1/10 the amount of Carbon-14 one…

A: Given, N= 1/10=0.1 No= 1 T= 5730years We know that, N= No(1/2)t/T

Q: The isotope cesium-137 has a half-life of 29.75 years. How long will it take a 100 gram sample of…

A: Given data The half-life of the cesium-137 is t1/2 = 29.75 years. The initial amount of the…

Q: The value of atomic mass unit is equivalent to 9.36 x 10-27 kg 1.66 x 10-32 kg 1.66 x 10-24 ka 1.66…

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A: Half-life is used to measure the decay rate of the radioactive isotope. One half-life is said to…

Q: A radioactive source has a half-life of 80 s. How long will it take for 7/8 of the source to decay?

A: Given, the half life a radioactive source =80 s we have to calculate the time for 7/8 of the source…

Q: A certain radioactive material has a half-life of 10 years. You have 80 kg of the material. After 10…

A: It is given that,

Q: The radioactive element 2760Co  has a half life of ______ years. If you had a sample of 17 g, about…

A: Given: The mass of sample (m) = 17 g. The half-life of cobalt (T1/2) = 5.27 years. The life of…

Q: cadmium -107 has a half -life of 6,52 hours .if you start off with sample which sample which has an…

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Q: If you know that the natural element samarium (its mass number 146) contains the radioactive isotope…

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Q: Elemental carbon has 6 protons and 6 neutrons. This is often described as carbon-12. Carbon-13 has 6…

A: Mass Number = Number of protons + Number of neutrons For Plutonium: Mass Number = 244 Number of…

Q: A certain radioactive substance has 122,200 atoms with a half-life of 12 minutes. NOTE: This is a…

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Q: . One isotope of oxygen has the atomic number 8 and the mass number 18. An atom of this isotope…

A: We know Isotopes have same atomic number (protons number ) but deferent mass number given oxygen has…

Q: The half-life of Unobtanium-118 is 3 days. How many days pass for 800 grams of this element to be…

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Q: The​ half-life of a radioactive substance is 20 years. If you start with some amount of this​…

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Q: What will happen when an electron returns to its original energy level?

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Q: f the half-life of cesium-137 is 30 years, approximately how much time will be required to reduce a…

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Q: If the half-life of an isotope is two years, what fraction of the isotope remains after six years

A: Amount of radioactive material after time t is given by: N = N0*exp(-lambda*t) lambda = decay…

Q: A radioactive isotope has a half-life of 51.5 days. What fraction of the isotope remains after 413…

A: We have: The half-life is t1/2=51.5 days Calculating the first-order reaction constant k as…

Q: A sample of a radioactive element has a half-life of 180 days; what percent of this sample will…

A: The decay constant of a radioactive sample is given by :  The amount of sample left after 't' time…

Q: One in 6500 water molecules contains a deuterium atom. If all the deuterium could be extracted from…

A: The total number of water molecule in 1 cubic meter is, Now the number of D-D fusion reaction is,

Q: half-life of an element is 20 years. In how many years will there be 12.5% of the initial material…

A: Given T1/2 = 20 years

Q: The half-life of a certain radioactive isotope is 30 minutes. If we start out with 100 g of the…

A: Given: Half-life (T1/2) = 30 min. = 0.5 h. Mass of the isotope (m) = 100 g. Time (t) = 2.0 h.

Q: The half-life of the radioactive element unobtanium-53 is 5 seconds. If 176 grams of unobtanium-53…

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Q: A silver coin has a mass of 17.75 g. If the atomic mass of silver is 107.868 u, how many silver…

A: mass = 17.75 g Atomic mass of silver = 107.868 u Number of moles of silver present in the coin =…

Q: Sketch a model of an atom, showing the positions of the subatomic particles protons, neutrons, and…

A: Protons p+ , neutrons n0 and electrons e- are subatomic particles.  p+have + ve charge. e-s have -ve…