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July 26, 2014

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

Number of results: 32,392

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...
June 27, 2014 by Anonymous

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...
June 27, 2014 by Anonymous

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...
June 27, 2014 by Anonymous

chemistry
When 3.761g of a hydrate of strontium chloride is heated to 60 degree C it forms strontium chloride dihydrate of mass 2.746g What is the formula of the original sample?
June 8, 2011 by aryan

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?
January 11, 2012 by Heather

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 ...
August 26, 2010 by Cratch

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 ...
July 3, 2012 by jessica

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?
November 11, 2011 by Mindy

chemistry
strontium chloride can be obtained as the anhydrous salt, SrCl2, and as the hydrates SrCl2.2H20, and SrCl2.6H20. (ArSr = 87.5). 0.323 g of a sample of strontium chloride is dissolved in water and reacted with sliver nitrate solution. The mass of sliver chloride precipitates is...
March 17, 2007 by kate

chemistry
Strontium has density of 2.64 and crystallizes with the face-centered cubic unit cell. Find the radius of the strontium atom
July 10, 2011 by hannah

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 ...
December 3, 2012 by Veronica

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
January 10, 2013 by Urgent Help

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?
April 27, 2011 by Help!!

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.
May 5, 2012 by Marie

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.
April 13, 2011 by alex

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.
April 13, 2011 by alex

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
December 19, 2013 by Dianna

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 ...
October 27, 2008 by Anna-Marie

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.
February 22, 2014 by sara

chemistry
what ins the name for SrBr2 Strontium (II) bromide strontium bromide
November 16, 2006 by queen

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. ...
April 13, 2008 by Sandhya

math
Daniel's print shop purchased a ner printer for $35000. Each year it depreciates (loses value) at a rate of 5%. what will its approximate value be at the end of the fourth year?
June 14, 2009 by Anonymous

physics
The moon is receding from the Earth by approximately 3.8 cm per year. Earth's mass is 5.98 x 10^24 kg, and its radius is 6.38 x 10^6 m. The Moon's mass is 7.3 x 10^22 kg, its radius is 1.79 x 10^6 m, and its orbital period around Earth is 27.3 days. The current average ...
December 16, 2008 by Michelle

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?
May 19, 2010 by Caitlyn

physical science
Determine the molar mass of the following elements: a. manganese, Mn c. arsenic, As b. cadmium, Cd d. strontium, Sr
December 4, 2008 by Jameisha

algebra
daniel's print shop purchased a new printer for $35'000.each year it depreciates (loses value ) at a rate 5%.what will its approximate value be at the end of the fourth year? 1)$33,250.00 2)$30,008.13 3)$28,507.72 4)$27,082.33
May 23, 2013 by harpreet

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...
February 17, 2014 by Brandon

economics
Tom plans to gamble each year for the next 20 years, starting at at the end of year 1. If he loses 4.47 dollars in odd years (i.e., years 1, 3, 5, etc) and wins 7.46 dollars in even years (i.e., years 2,4, 6 etc), what will be Tom's (internal) rate of return per year from ...
April 17, 2011 by Rachel

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 ...
January 13, 2011 by Brittany

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 ...
August 28, 2012 by Jason

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 ...
September 19, 2012 by Annie

chemistry
6.25 L of a propanoic acid-propanoate buffer must be prepared. The pH of the buffer needs to be 5.05. The solution will be 0.120M in propanoic acid. If the propanoate ion comes from the strontium propionate Sr(C3H5O2)2 then how many grams of strontium propanoate are needed?
March 1, 2013 by Studious

chemistry
write ionic equation for : potassium carbonate and sodium sulfate sulfuric acid and strontium chloride potassium phosphate and sodium hydroxide sodium hydroxide and strontium chloride
October 23, 2011 by ceezale

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?
April 6, 2010 by bob

chemistry
The solubility of strontium oxide, SrO, in water is 22.8 g per 100 mL at 100 ░C and 0.69 g per 100 mL at 30 ░C. Is the dissolving of strontium oxide in water an endothermic or exothermic process?
January 10, 2013 by Alex

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 ...
October 6, 2009 by Z32

Chem 20
Calculate the mass of strontium hydroxide required to make a 450-mL solution with a pOH of 4.00. Step 1: Find pOH. I found that pOH is 10. The next steps is where I'm stuck. Step 2 :Calculate the hydroxide ion concentration. Express your answer in scientific notation. Spell ...
November 29, 2010 by Anonymous

English
In the third scaffold scene of The Scarlet Letter, it is said that Dimmesdale regains his soul, Pearl gains humanity, Chillingworth loses his victim, and Hester loses her dreams. Can you please explain how the events take place in depth?
October 16, 2012 by Karissa

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 10^3 kJ of energy. a) Write the...
February 1, 2007 by Jess

Chemistry
During the electrolysis of an aqueous solution of CuSO4 with inert electrodes (A) the anode loses mass and the cathode gains mass. (B) the mass of the anode remains the same but the cathode gains mass. (C) the mass of the anode decreases but the mass of the cathode remains ...
May 12, 2008 by LT

10th grade
calculate the mass of the water of hydration if a hydrate loses 0.025 mol of H2O when heated
November 2, 2010 by Sherry

phsyics
A mass, m1 = 9.36 kg, is in equilibrium while connected to a light spring of constant k = 112 N/m that is fastened to a wall. A second mass, m2 = 6.71 kg, is slowly pushed up against mass m1, compressing the spring by the amount A = 0.201 m The system is then released, and ...
November 5, 2009 by Anonymous

english
does anyone know how ruby mcqueens lost her innocence in the story honey, baby, sweetheart. i really need help. what i wrote before was that she loses innocence through falling in love with travis becker but i need to more points to prove that she loses her innocent
April 12, 2011 by ted

physics
A building has become accidentally contaminated with radioactivity. The longest-lived material in the building is strontium-90. (The atomic mass of Sr is 89.9077 u.) If the building initially contained 4.8 kg of this substance and the safe level is less than 10.0 counts/min, ...
June 3, 2012 by andrew

Science
If a loaded truck that can accelerate at 1 m/s2 loses its load and has one-half of the original mass, what acceleration can it attain from the same driving force?
May 20, 2014 by Justin Wyms

Math
In a series of three plays, a college football team had the following results:loses 5 yards, gains 8 yards, and loses 7 yards. Find the net gain (or loss) after this series. The answer is suppose to be 4. ( I keep getting -4)
January 27, 2010 by Stacey

physics
If a loaded truck that can accelerate at 1 m/s2 loses its load and has four-fifths of its original mass, what acceleration can it attain if the same driving force acts on it?
October 11, 2010 by Anonymous

physics
A child loses his balloon, which rises slowly into the sky. If the balloon is 13 cm in diameter when the child loses it, what is its diameter at the following altitudes? Assume that the balloon is very flexible and so surface tension can be neglected. (a) 2200 m
March 23, 2012 by sara

physics
A child loses his balloon, which rises slowly into the sky. If the balloon is 17 cm in diameter when the child loses it, what is its diameter at the following altitudes? Assume that the balloon is very flexible and so surface tension can be neglected. (a) 1100 m (b) 1900 m (c...
April 16, 2011 by Anonymous

math
Beth plays a video game in which she starts with 0 points. In round 1, she loses 3 1/2 points. In round 2, she wins 28 1/2 points, and in round 3 she loses another 3 1/2 points. What is her final.score?
January 1, 2014 by Please Help!!!

physics
A mass, m1 = 5.5 kg, is in equilibrium while connected to a light spring of constant k = 132 N/m that is fastened to a wall (see a). A second mass, m2 = 10.9 kg, is slowly pushed up against mass m1, compressing the spring by the amount Ai = 0.17 m (see b). The system is then ...
February 6, 2013 by Anonymous

algebra
kathy plans to purchase a car that depreciates (loses value)at a rate of 14%per year initial cost of the car ia $21,000.which equation represents the value,v,of the car after 3 years?
May 23, 2013 by harpreet

chemistry
how many electrons does Fe3+ gain or lose when the ion forms? A. gains 1 electron B. loses 1 electron C. gain 3 electrons D. loses 3 electrons I think D.
November 20, 2012 by drew

physics
A car of mass 1500 kg traveling at 15.6 m/s loses its brakes and collides with the rear end of the car in front of it, which has a mass of 1020 kg and is traveling in the same direction at 12.5 m/s. If the smaller car is given a speed of 15.3 m/s by the collision, what is the...
April 18, 2013 by YOLO

Math
A share of stock worth 100 dollars loses 90% of its value. Then, over the next year, the value of the stock increases by 90%. What is the new value of the stock?
October 30, 2011 by Britt Nicole

math
A share of stock worth 100 dollars loses 90% of its value. Then, over the next year, the value of the stock increases by 90%. What is the new value of the stock?
October 30, 2011 by Maddi Jane <3

science
Is strontium chloride a ionic or covalent bond?
October 24, 2007 by flowerpower

earth
strontium working with water is it physical or chemical
March 13, 2008 by polly

Scienc
World poplation grow each year,does this mean the mass off earth increases each year? Why?
October 25, 2007 by Nazharia Zehr

University Chemistry (first year)
I'm working on a first year chemistry lab where we synthesized alum from alunimini foil and I'm doing the report and one of the questions is as follows: Based on your findings, what volume of water can be cleared of suspended solids by one beverage can (give a range in L)? (...
October 17, 2011 by clam

Algrebra II
In this word problem, I have to assume that it can be described by a linear function: A photocopying machine purchased new for $4500 loses $900 in value each year. a) Find the value of the machine after 18 months. b) When will the book value be $1200? Thank you for helping me ...
November 11, 2008 by Maria

11th grade chemistry
whats the ionic name for strontium iodide
November 20, 2008 by latifa

physics
Calculate the number density of strontium titanate (SrTiO3), ρ = 5.12 g cm -3
January 15, 2011 by Bobby

chemistry
What are the products of the reaction between nitrous acid and strontium hydroxide?
April 20, 2014 by Candy

Physics
A spring with a spring constant of 223.9 N/m is compressed by 0.220 m. Then a steel ball bearing of mass 0.0372 kg is put against the end of the spring, and the spring is released. What is the speed of the ball bearing right after it loses contact with the spring? (The ball ...
September 21, 2010 by Gina

Algebra 2
A photocopying machine purchased new for $4500 loses $900 in value a each year. a. Find the book value of the machine after 18 months. b. When will the book value be $1200? Assume that each situation can be decribed as a linear equation HELP!!! I don't know how to set this up ...
August 31, 2010 by Jessica

Business Law
Fred Salem works as a sales rep for Pennrock Greeting Cards. He has a three-year contract but quits after two years. As a result, Pennrock loses sales of $1000. May Pennrock recover this amount from Salem?
July 30, 2011 by Sarah

Chemistry
Is the reaction between sodium sulfate and strontium nitrate endothermic or exothermic and why?
March 5, 2014 by Lily

math
A full grown oak tree loses an average of about 7 tons of water through its leaves per day. About how many tons of water is that per year? I need an exact answer using partial products. Can anyone please hlep?
December 4, 2007 by Becky

chemistry
A 2.500 gram sample of hydrate of calcium sulfate loses 0.532 grams of water when heated. Determine the mass percent of water in the hydrate and the formula of the hydrate.
February 27, 2010 by lauren

Chemistry
What is the net ionic equation for the reaction that occures between nitrouse acid and strontium hydroxide ?
February 22, 2012 by Cynthia

Chemistry
A certain mine produces 2.5 108 kg of copper from chalcopyrite (CuFeS2) each year. The ore contains only 0.80% Cu by mass. (a) If the density of the ore is 2.0 g/cm3, calculate the volume of ore removed each year. (b) Calculate the mass of SO2 produced by roasting (assume ...
April 13, 2007 by Chemistry

Science/Math
If a barrier island that is 1km wide and 10km long loses 1.5 m of its width per year to erosion by a longshore current, how long will teh island take to loose one-fourth of its width. Please show step by step how to work this problem. Thank you
February 27, 2009 by Dan1

Chemistry
How do I find the POtential Energy for a reaction from strontium chloride and potassium carbonate? and what is the chemical reactions for the above
November 30, 2011 by SBB

chemistry
calculate how much strontium fluoride will dissolve in 1L of water given Ksp= 2.5x10^-9 at 25 degree celsius
June 3, 2012 by lily

physics
if a pendulum clock keeping at sea level is taken at depth h=1km below sea level then the clock approximately gives time is a.gain 13.5 s per day b.loses 13.5s per day c.loses 7 s per day d.gains 7 s per day
January 13, 2014 by risang_tamang

Economics(Please respond, thank you)
The table below shows the market basket quantities and prices for the base year (year 1) Base year 1 Price in price Quantity base year yr 2 Product Pizza 15 $3 $3.75 t-shirts 4 $10 $9 rent 1 $500 $550 In year 1 the CPI was? In year 2 the CPI was? I know that cpi= (expenditures...
March 18, 2012 by Hannah

Ecomonics(Urgent,please respond)
The table below shows the market basket quantities and prices for the base year (year 1) Base year 1 Price in price Quantity base year yr 2 Product Pizza 15 $3 $3.75 t-shirts 4 $10 $9 rent 1 $500 $550 In year 1 the CPI was? In year 2 the CPI was? I know that cpi= (expenditures...
March 18, 2012 by Hannah

CHEMISTRY
When 2.47 g of chromium is reacted with an excess of sulphur, the compound Cr2S3 results. Treating the Cr2S3 so formed with strontium metal converts all of the sulphur to SrS. Reacting the SrS with sodium metal then converts all the SrS to Na2S. What mass in grams of Na2S is ...
November 3, 2007 by Matt

AP Chem
Write the net ionic formula. A bar of strontium metal is immersed in a 1.0 M copper (II) nitrate solution. How do I go about doing this?
October 3, 2007 by Needs help

Chem
What 4 quantum numbers describes one of the outermost electrons in a strontium atom in ground state? 5,0,0,1/2 Is my answer correct?
July 7, 2009 by Lena

Chemistry
How do you calculate the molar masses for Strontium Phosphate and Chromium(III)Nitride using significant figures correctly?
January 3, 2010 by Katie

Chemistry
Will you check this answer for me? the half-life of strontium-87 is 2.8hr. What percentage of this isotope will remain after 8 hours and 24 minutes? ?? 34%
May 25, 2011 by Madison

physics
a) 2.0 kg of molten copper at its melting point of 1083 ║C (the copper is 100% liquid) is poured into a mold in a cooling water bath at 20 ║C. What mass of water is needed to bring the solidified copper and water to an equilibrium temperature of 30 ║C, assuming the only heat ...
December 12, 2006 by Eric

physics
a person pulls a box vertically out of water with an acceleration of 3m/s^2 using a very light rope that has a breaking strength of 22N. the person loses the box as the line snaps. what can you say about the mass of the box?
April 5, 2009 by Nat

Algebra
On its first three plays in a football game, the offense gains 6 yards,loses 5 yards, and then gains 7 yards. Write an equation that could be used to find y, the number of yards needed on the fourth play for the overall 10-yard gain required for the first down. Could you ...
January 6, 2009 by Rachel

Math
Suppose the first Friday of a new year is the fourth day of that year. Will the year have 53 Fridays regardless of whether or not it is a leap year? What is a rule that represents the sequence of the days in the year that are Fridays? How many full weeks are in a 365 day year...
November 17, 2013 by Anonymous

math
A town has a population of 32,000 in the year 2002; 35,200 in the year 2003; 38,720 in the year 2004; and 42,592 in the year 2005. If this pattern continues, what will the population be in the year 2016?
March 10, 2012 by Brittany

Physics
ôStrontium-90 is a pure beta source.ö How could a physicist test this statement? I am stuck on this one, but I was thinking through measurement of radioactivity.
August 30, 2013 by Charles

physics
A child loses his balloon, which rises slowly into the sky. a) If the balloon is 21.5 cm in diameter when the child loses it, what is its diameter at an altitude of 1150 m? Assume that the balloon is very flexible and so surface tension can be neglected. b) And what is the ...
March 21, 2012 by maria

physics
A firework rocket is launched vertically from rest and loses 60% of its mass during a burn time of 4 seconds. What is the final speed of the rocket relative to the ground (in m/s) when the gas relative to the rocket has a speed v= 80 m/s? a. 15 m/s; b. 34 m/s; c. 68 m/s; d. ...
December 29, 2013 by Ken

physics
An astronaut in her space suit has a total mass of m1 = 69.7 kg, including suit and oxygen tank. Her tether line loses its attachment to her spacecraft while she's on a spacewalk. Initially at rest with respect to her spacecraft, she throws her oxygen tank of mass m2 = 12.0-kg...
October 25, 2011 by Anonymous

Physics 1
An astronaut in her space suit has a total mass of m1 = 76.9 kg, including suit and oxygen tank. Her tether line loses its attachment to her spacecraft while she's on a spacewalk. Initially at rest with respect to her spacecraft, she throws her oxygen tank of mass m2 = 12.0-kg...
March 14, 2013 by Emily

finance
Thompson stores is considering a project that has the following cash flow data. What is the project's IRR. Note that a project's projected IRR can be less than the WACC and even negative, in which case it wll be rejected. Year 0 ($1,000), year 1 $300, year 2 $295, year 3 $290...
February 6, 2010 by vince

Chemistry
If equal masses of Sodium and Strontium were reacted with excess hydrochloric acid, which experiment would produce a greater volume of hydrogen gas?
November 12, 2009 by Lillian Nguyen

sicence
The following elements as alkali, alkaline-earth or transition metals based on their positions in the periodic table: A:) iron , Fe. C:) strontium, Sr B:)potassium, k d:) platinum, Pt
January 27, 2013 by makayla

Science help
For each of the following what type of smallest particle would exist? explain your reasoning? a.) strontium B.) CaCl2 C.) CCl4 D.) SO2 E.) helium F.) bromine G.) MgO Thanks :):):):)
March 2, 2014 by Anonymous

Math(Statistics)
A certain soccer team wins (W) with P(W)= 60%, loses(L) with P(L) = 30%, and ties (T) with P(T) = 10%. The team plays three games over the weekend. a.Determine the elements of the event A that the team wins at least twice and does not lose. b.Find P(A) c.Determine the elements...
October 5, 2011 by Anonymous

Math
A certain soccer team wins (W) with P(W)= 60%, loses(L) with P(L) = 30%, and ties (T) with P(T) = 10%. The team plays three games over the weekend. a.Determine the elements of the event A that the team wins at least twice and does not lose. b.Find P(A) c.Determine the elements...
October 7, 2011 by Anonymous

Physics
What is the period of Earth's (nearly) circular motion around the Sun? (2*pi*r)/T 1 year (1 year)/(2*pi) (2*pi)/(1 year) 2*pi*(1 year)
September 22, 2012 by StressedStudent

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