# Strontium 90 loses 2.5% of its mass each year. What is its half life?

58,334 results

### Forensics

Strontium-90 is a radioactive waste product from nuclear reactors. It has a half life of 29 years. How many years would it take for a quantity of strontium-90 to decay 1/16 of its original mass?

### AP Environmental Science (URGENT)

Strontium-90 is a radioactive waste product from nuclear reactors. It has a half-life of 29 years. How many years will it take for a quantity of strontium-90 to decay to 1/16 (one-sixteenth) of its original mass?

### Math

Suppose strontium-90 decays at a rate of 2 percent per year. (a) Write the fraction P of strontium remaining, as function of t, measured in years. (Assume that at time t=0 there is 100 % remaining.) Answer: P(t) = (b) Estimate the half-life of strontium. Answer: Hint: Use your...

### calculus

Suppose strontium-90 decays at a rate of 2 percent per year. (a) Write the fraction P of strontium remaining, as function of t, measured in years. (Assume that at time t=0 there is 100 % remaining.) Answer: P(t) = (b) Estimate the half-life of strontium. Answer: Hint: Use your...

### NEED HELP WITH CALC

Suppose strontium-90 decays at a rate of 2 percent per year. (a) Write the fraction P of strontium remaining, as function of t, measured in years. (Assume that at time t=0 there is 100 % remaining.) Answer: P(t) = (b) Estimate the half-life of strontium. Answer: Hint: Use your...

### Calculas

In the early 1960s, radioactive strontium-90 was released during atmospheric testing of nuclear weapons and got into the bones of people alive at the time. If the half-life of strontium-90 is 32 years, what fraction of the strontium-90 absorbed in 1965 remained in people's ...

### calculus

In the early 1960s, radioactive strontium-90 was released during atmospheric testing of nuclear weapons and got into the bones of people alive at the time. If the half-life of strontium-90 is 27 years, what fraction of the strontium-90 absorbed in 1962 remained in people's ...

### Chemistry

The half-life for beta decay of strontium-90 is 28.8 years. A milk sample is found to contain 10.3 ppm strontium-90. How many years would pass before the strontium-90 concentration would drop to 1.0 ppm?

### chemistry

Strontium-90 decays through the emission of beta particles. It has a half-life of 29 years. How long does it take for 80% of a sample of strontium-90 to decay? Show process of how you got this

### Math

The element strontium-90 is radioactive. The percent of strontium -90, A(t), left in a sample can be modelled by the half-life function A(t) = A0 (1/2)^t/29, where t represents the time, in years, after the initial time, and A0 represents the initial amount, 100% of the ...

### Chemistry

Strontium-85, used for bone scans, has a half-life of 64 {\rm d}.How long will it take for the radiation level of strontium-85 to drop to \frac{1}{8} of its original level?

### Math

The half-life of strontium-90 is 28 years. How long will it take a 60 mg sample to decay to a mass of 15 mg?

### chem

Radioactive substances decay by first-order kinetics. How many years would be required for a sample containing strontium-90 to decrease to 58.32% of its initial activity? The half-life of strontium-90 is 2.88e1 years.

### Science Help

i know that the half life of strontium 90 half-life is 28.8 but how can i explain this???

### chemistry

Strontium-90 has half-life of 28 years. if a 1.00-mg sample was stored for 112 years. what mass of Sr-90 would remain?

### Calculus

The half-life of radioactive strontium-90 is approximately 31 years. In 1960, radioactive strontium-90 was released into the atmosphere during testing of nuclear weapons, and was absorbed into people's bones. How many years does it take until only 11 percent of the original is...

### SCIENCE

We did a radioactive decay and half life lab with m&ms and I do not understand these conclusion questions: 1. how many half lives would it take for 500 nuclei to decay to 6.25% of the original number of nuclei? My ans: 3125?- do not think that's right! 2. Is there any way to ...

### Calculus

The half-life of radioactive strontium-90 is approximately 31 years. In 1960, radioactive strontium-90 was released into the atmosphere during testing of nuclear weapons, and was absorbed into people's bones. How many years does it take until only 11 percent of the original ...

### Math

The half-life of radioactive strontium-90 is approximately 28 years. In 1962, radioactive strontium-90 was released into the atmosphere during testing of nuclear weapons, and was absorbed into people's bones. How many years does it take until only 6 percent of the original ...

### Math

The half-life of radioactive strontium-90 is approximately 32 years. In 1961, radioactive strontium-90 was released into the atmosphere during testing of nuclear weapons, and was absorbed into people's bones. How many years does it take until only 8 percent of the original ...

### Science

Can anyone help me find the half-life of strontium-90? I also need an explanation on how to do it. Thanks!! Radioactive Decay of Strontium-90: At 0 years: 100% remaining At 28 years: 50% remaining At 56 years: 25% remaining At 84 years: 10% remaining At 112 years: 5% remaining.

### Calculus

[Exponential growth & decay] The half-life of radioactive strontium-90 is approximately 29 years. In 1965, radioactive strontium-90 was released into the atmosphere during testing of nuclear weapons, and was absorbed into people's bones. How many years does it take until only ...

### Chemistry

Strontium metal is responsible for the red color in fireworks. Fireworks manufacturers use strontium carbonate, which can be produced by combining strontium metal, graphite (C), and oxygen gas. The formation of one mole of SrCO3 releases 1.220 x 103 kJ of energy. a) Write a ...

### Chemistry

The half life of U238 is 4.5 x 10^9 yr. A sample of rock of 1.6 g produces 29 dis/sec. Assuming all radioactivity is due to U238 find percent by mass of U 238. I have tried ln(t)/ln(0)= -kt and still cannot get the answer What I get is A) 4.5x10^9 x365x60x60x24=1.419x10^17 for...

### Math

A new car typically loses 20% of its initial value during the first year. During the second year, the car loses 15% of its value after the first year. Find the value of the car after the first year and after the second year.

### Earth Science

Why is potassium-argon dating most applicable to dating very old rocks? potassium’s long half-life potassium’s short half-life argon’s long half-life argon’s short half-life

### chem

If the passing of three half-lives leaves 33.1 mg of a strontium-90 sample, how much was present in the beginning?

### Science

A star's life depends on mass ___ mass=Long life Large mass= ____ life Small mass is long life and large mass is short life?

### Chemistry

Technetium-99m is an ideal radioisotope for scanning organs because it has a half-life of 6.0 hr and is a pure gamma emitter. Suppose that 200mg were prepared in the technetium generator this morning. How many milligrams would remain after the following intervals? 1- One half ...

### Chemistry

Technetium-99m is an ideal radioisotope for scanning organs because it has a half-life of 6.0 hr and is a pure gamma emitter. Suppose that 200mg were prepared in the technetium generator this morning. How many milligrams would remain after the following intervals? 1- One half ...

### Chemistry

Technetium-99m is an ideal radioisotope for scanning organs because it has a half-life of 6.0 hr and is a pure gamma emitter. Suppose that 200mg were prepared in the technetium generator this morning. How many milligrams would remain after the following intervals? 1- One half ...

### chemistry

The radius of a strontium atom is 215 pm. How many strontium atoms would have to be laid side by side to span a distance of 4.47 mm?

### chemistry

The radius of a strontium atom is 215 pm. How many strontium atoms would have to be laid side by side to span a distance of 2.66 mm?

### college

. S-35 (t1/2 = 87.4 d) is used in cancer research. The biological half-life in the human body is 90 days. What is the effective half-life of S-35?

### Math

The mathematician Augustus DeMorgan lived his entire life during the 1800s. In the last year of his life he announced "Once I was x years old in the year x^2". In which year was he born?

### college chem

S-35 (t1/2 = 87.4 d) is used in cancer research. The biological half-life in the human body is 90 days. What is the effective half-life of S-35?

### chemistry

A given reaction has an activation energy of 24.52 kJ/mol. At 25C the half-life is 4 minutes. At what temperature will the half-life be reduced to 20 seconds?

### Chemistry

Why does the height of the precipitate of strontium nitrate and sodium carbonate go up as the volume of strontium nitrate increase?

### chemistry

1-Barium sulfate and strontium sulfide both are placed into beaker of water. a- Will the strontium sulfide dissociate? ....... - If it does,write the equation showing the dissociation.

### Physics

Gold-198 with a half life of 2.6 days is used to diagnose and treat liver disease. Write a half life decay equation that relates the mass of au-198 remaining to time in days. What percentage of a sample of Au-198 would reamin after 1 day, 1 week? Given the information, I could...

### college chemistry

If the equilibrium constant (Keq) equals 9.12x1012 for the following reaction between strontium and magnesium: Sr(s) + Mg2+(aq)<==> Sr2+(aq) + Mg(s) Calculate Eo for a strontium=magnesium battery.

### college chemistry

If the equilibrium constant (Keq) equals 9.12x1012 for the following reaction between strontium and magnesium: Sr(s) + Mg2+(aq)<==> Sr2+(aq) + Mg(s) Calculate Eo for a strontium=magnesium battery.

### chemistry

If I 131 has a half-life of 8 days, what fraction will be left after a year?

### chemistry

what is the percentage yield for Sr(NO3)2 + Na2SO4 -> SrSO4 + 2 NaNO3. mass of strontium nitrate is 0.788g mass of sodium sulfate is 1.258g mass of dry filter paper 0.759 g mass of dried precipitate in filter paper 1.317g

### help huge test friday science

I cant grasp half life - the study guide question is how is half life dating used by scientists - I have 2 lines to write an answer

### 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?

### AP Chem

I know this might sound easy... but i need these problems for bonus and i want to make sure they are right Silver nitrate reacts with strontium chloride in an aqueous precipitation reaction. What are the formulas of silver nitrate and strontium chloride? Write the molecular ...

### Physics (Inside the atom)

A sample of radioactive isotope I is to be used for medical diagnosis of the kidneys. The isotope has a half-life of 8.0 days, and the sample is required to have an activity of 8 x 10^5 per second at the time it is given to the patient. Calculate the mass of the I-131 present ...

### Physical Science

A gram of radioactive material has a half-life of one year. After four years how much radioactive material will be left...0g, 1/2g, or 1/4g? None of the above. The answer one-half to the fourth power.

### 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.

### Calculus

Radius decays at a rate of that is proportional to its mass, and has a half-life of 1590 years. If 20 g of radium is present initially, how long will it take for 90% of this mass to decay?

### math

You have just isolated a new radioactive element. If you can determine its half-life, you will win the Nobel Prize in physics. You purify a sample of 2 grams. One of your colleagues steals half of it, and eight days later you find that 0.1 gram of the radioactive material is ...

### chemistry

what ins the name for SrBr2 Strontium (II) bromide strontium bromide

### math

Suppose your bank account was worth \$1000 at the beginning of last year. If your balance increased by 3% during the first half of the year and by 2% during the second half, what was your balance at the end of the year?

### Atomic physics

1)Five possible transitions for a hydrogen atom are listed below: Select whether the atom gains or loses energy for each transition. a. Loses Gains ni = 6; nf = 4 Loses Gains ni = 4; nf = 2 Loses Gains ni = 5; nf = 3 Loses Gains ni = 2; nf = 5 Loses Gains ni = 5; nf = 7 b. ...

### science

Cobalt-60 has a 30 year half-life. How much of an 80 gram sample would remain after 60 years?

### Math

The U.S life expectancy of a baby born in 1960 was 69.8 years. For a birth year of 2010, the U.S life expectant was 78.5 years. Let Y be the US life expectancy for a baby born in the year x, where x=0 represents the year 1960. What would the life expectancy for a baby born in ...

### algebra

Suppose a sample of Cesium-137 with initial mass of 200 grams decays to a mass of 160 grams voer the course of 10 years. Find the half-life of Cesium-137 (Round to the nearest year) How much Cesium-137 is left in the sample after 60 years? Round to the nearest tenth of a gram.

### Half-life

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

### Physics - Half life

an artifact has a starting mass of C-14 of 200 g and a remaining mass of 0.78125 g. how old if the artifact? [4.58^4 years]

### calculus

The half-life of Radium-223 is 11.43 days. If a sample has a mass of 900 mg, find the mass (in mg) that remains after 5 days

### calculus

The half-life of Radium-223 is 11.43 days. If a sample has a mass of 400 mg, find the mass (in mg) that remains after 6 days