Tuesday
July 22, 2014

Search: 2. Explain how radioactive decay has always warmed the Earth from the inside, and nuclear fusion has always warmed Earth from the outside

Number of results: 29,221

physis
Search: 2. Explain how radioactive decay has always warmed the Earth from the inside, and nuclear fusion has always warmed Earth from the outside.
January 26, 2014 by barbara

Physics
Explain how redioactive decay has always warmed the Earth from the inside and how nuclear fusion has always warmed the Earth from the outside.
April 25, 2008 by Rob

Science- Radioactive Dating
Which of the following statements about radioactive dating is true? a. Radioactive decay is the rate at which new atoms form. b. During radioactive decay, atoms break down, releasing particles or energy. c. The rate of decay of a radioactive element cannot be approximated. d. ...
October 10, 2013 by Anonymous

earth science
how does radioactive decay provide heat energy within the earth
July 19, 2008 by kate

calculus
Carbon-14 is a radioactive substance produced in the Earth's atmosphere and then absorbed by plants and animals on the surface of the earth. It has a half-life (the time it takes for half the amount of a sample to decay) of approximately 5730 years. Using this known piece of ...
July 24, 2009 by j

Physics
Hi Radioactive decay - A radioactive nuclide has a decay constant of - 10^-6 s-1 what is its half life ? I have come up with is IN (2) / 0.000001 s-1 = 693147.18055 which iam having troube working into real figures Can anyone help please .. thanks
August 24, 2013 by Freddo

Physics ...
Hi Radioactive decay - A radioactive nuclide has a decay constant of - 10^-6 s-1 what is its half life ? I have come up with is IN (2) / 0.000001 s-1 = 693147.18055 which iam having troube working into real figures Can anyone help please .. thanks
August 24, 2013 by Freddo

earth
3. What can scientists learn from the rate at which radioactive elements decay?
December 10, 2013 by Elizabeth

science
Which statement best explains why dating geologic materials from the Quarternary Period uses a different radioactive isotope than for materials from the cambrian Period? a. all rocks contain radioactive substances. b. some isotopes decay faster than others. c. not all isotopes...
April 4, 2009 by Angie

8th Grade Earth Science Help?
Which of the following terms refers to the time it takes for one-half of the radioactive atoms in a sample of a radioactive element to decay? - relative age - absolute age - potassium-argon data - half-life** Is my answer correct?
January 14, 2014 by Rainshine

Chemistry
How many half lives will it take for a sample of a radioactive isotope containing 20000 radioactive nuclei to decay to 2000 radioactive nuclei
November 16, 2010 by Dianne

Earth Science
1. Is it true that since energy cannot be created nor destroyed, the total energy of the river system remains constant? 2. What is the source of energy that powers the water cycle? a. sunlight insolation b. kinetic energy c. radioactive decay d. gravitational potential energy ...
November 24, 2008 by John

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 notation, ...
January 17, 2013 by Quinn

radioactive decay
What elements results if one of the neutrons is in a nitrogen neucleus is converted by radioactive decay into a proton? The atomic number goes from 7 to 8, while the atomic weight stays the same. An electron (beta-) is emitted from the nucleus. Actually, this process does not ...
June 28, 2005 by Jarrad Schomaker

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.
January 18, 2011 by Justin

MATH!
The mass of a radioactive substance follows an exponential decay model, with a decay rate of 5% per day. A sample of this radioactive substance was taken six days ago. If the sample has a mass of 3 kg today, find the initial mass of the sample. Round your answer to two decimal...
March 15, 2012 by Kim

science
A 10g sample of radioactive substances is lift to decay for five half-lives. How much of the radioactive substance remains?
February 19, 2013 by mirian hernandez

chemistry -- radioactive decay
suppose you have a 150 gram sample of radioactive decay god-191 which has a half- life of 3.4 hours. how many grams of gold will ramain after 10hrs ? after 24 hrs? answer : 10 hrs :10/3.4= 2.94 times 150*(1/2)^2.94 = 18.75 grams 24 hrs: 24/3.4 = 7.06 150*(1/2)^7.06= 1.12 right...
September 18, 2012 by Maria

Science- Earth and its History
What can scientists learn from the rate at which radioactive elements decay? A. a rock's absolute age* B. the relative age of rock layers C. where one soil horizon ends and the next begins D. the difference between molds and casts. After six half-lives, what percentage of a ...
October 15, 2013 by Anonymous

Algebra
What are some real-life examples of exponential decay? Please help me think of some ideas...except radioactive decay.
January 30, 2014 by Anonymous

math
39mg radioactive with 1/2 life is decay total in 2.5 years. How many mg it remain if half of the amount is decay in 2 years? Thank you!
June 18, 2010 by Marie

physics
if 5/6th of a radioactive sample decay in 70 years and 1/6th remain. how can you find the half life without knowing the decay constant can you help?
May 21, 2008 by ronny

chemistry
a certain radioactive nuclide has a half life of 5.00 hour. Calcuate the decay rate for 1.000 mole of this nuclide __________ decay s-1
July 12, 2012 by eric

mathematics
what is the equation for exponetial decay(radioactive decay) and how to use the half life in the equation
November 2, 2011 by anonymous

Science [Earth]
Can you please: 1. briefly explain the concept of radioactive decay and describe how it can be used to find the absolute age of rocks. 2. contrast relative age with absolute age and describe at least three methods of determining either. 3. compare advantages and disadvantages ...
May 8, 2009 by xxx

science
during radioactive decay atoms of a radioactive element break down and change into other atoms of another element-all at once a) true b) false
December 11, 2013 by victoria

Math-Exponential Decay
A lab technician had 58 grams of a radioactive substance. Ten days later, only 52 grams remained. Find the half-life of the radioactive substance.
May 12, 2014 by Anonymous

chemistry
How long will it take for 25% of the C-14 atoms in a sample of C-14 to decay? The half-life for the radioactive decay of C-14 is 5730 years. If a sample of C-14 initially contains 1.1 mmol of C-14 , how many millimoles will be left after 2275 years?
February 28, 2010 by Anonymous

Science
What can scientists learn from the rate at which radioactive elements decay? A. a rock's absolute age* B. the relative age of rock layers C. where one soil horizon ends and the next begins D. the difference between molds and casts. After six half-lives, what percentage of a ...
October 15, 2013 by Anonymous

Science
What can scientists learn from the rate at which radioactive elements decay? A. a rock's absolute age* B. the relative age of rock layers C. where one soil horizon ends and the next begins D. the difference between molds and casts. After six half-lives, what percentage of a ...
October 16, 2013 by Anonymous

Science
What can scientists learn from the rate at which radioactive elements decay? A. a rock's absolute age* B. the relative age of rock layers C. where one soil horizon ends and the next begins D. the difference between molds and casts. After six half-lives, what percentage of a ...
October 16, 2013 by Anonymous

Calculus-Modeling Equations
An unknown radioactive element decays into non-radioactive substances. In 420 days the radioactivity of a sample decreases by 39 percent. 1.What is the half-life of the element? 2.How long will it take for a sample of 100 mg to decay to 46 mg?
March 6, 2009 by Kim

chemistry
A particular radioactive substance has a half-life of 4 minutes. How long will it take for 250 g of this radioactive material to decay to less than 0.1g? 24 min 36 min 40 min 48 min 72 min I got 32 min but that not one of the choices. Please help
December 5, 2011 by Anonymous

algebra
Scientists can determine the age of ancient objects by a method called radio carbon dating. The bombardment of the upper atmosphere by cosmic rays converts nitrogen to a radioactive isotope 14C of carbon with a half-life of about 5710 years. Vegetation absorbs carbon dioxide ...
March 7, 2013 by Emily

Chemistry
Pu-238 is radioactive by alpha-decay (half-life 87.7 y). Each decay releases 5.6 MeV of energy. Pu-238 is sometimes used to power space probes. If all the decay energy can be converted to electric power, what mass of Pu-238 would be required to power a 22 kW space probe for at...
October 15, 2013 by Jane

chem
Pu-238 is radioactive by alpha-decay (half-life 87.7 y). Each decay releases 5.6 MeV of energy. Pu-238 is sometimes used to power space probes. If all the decay energy can be converted to electric power, what mass of Pu-238 would be required to power a 22 kW space probe for at...
October 16, 2013 by Jane

science
Calculate the uranium ratios in the natural uranium decay chain using radioactive decay relationships. Compare to the value obtained using published natural abundances.
January 29, 2011 by Anonymous

Algebra 2 help...
A half life of a certain radioactive is 36 days. An initial amount of the material has a mass of 487 kg. Write an exponential function that models the decay of this material. Find how much radioactive material remains after 5 days. Round your answer to the nearest thousandth.
January 10, 2014 by Maria

Algebra
A defective nuclear reactor is leaking radioactive iodine-131. The rate of decay of iodine-131is given by the function defined by A(t)=A_0 e^(-0.087t), where t is time in days. How long will it take any quantity of iodine-131 to decay to 25% of its initial amount?
June 19, 2013 by AZ

chemistry
Write a partial decay series for Po-214 undergoing the following sequential decays: , , , . Use e for an electron. Use the format +1 or -1 for charge. a)a decay b) decay c)a decay d) decay
September 30, 2010 by lisa

Math
A radioactive substance decays according to the formula Q(t) = Q0e−kt where Q(t) denotes the amount of the substance present at time t (measured in years), Q0 denotes the amount of the substance present initially, and k (a positive constant) is the decay constant. (a) ...
April 5, 2014 by Vanessa

Math
A radioactive substance decays according to the formula Q(t) = Q0e−kt where Q(t) denotes the amount of the substance present at time t (measured in years), Q0 denotes the amount of the substance present initially, and k (a positive constant) is the decay constant. (a) ...
April 6, 2014 by Vanessa

science
describe how radioactive isotopes decay
December 5, 2010 by kayla

Physical Science
What is an example of radioactive decay?
October 13, 2011 by Brooke

phys
Although most natural potassium nuclei are stable 39K (93.3%) or 41K (6.7%) nuclei, about 0.0117% are radioactive 40K nuclei, which have a half-life of 1.26 billion years. What fraction of all the potassium nuclei in your body will undergo radioactive decay in the next 1.04-...
June 6, 2013 by Anonymous

chem
Complete the following radioactive decay problem. 234 4 U ---> He+ 92 2 how do i do this?
May 20, 2011 by Alie

Science
How is nuclear radiation produced? What are 3 types of radioactive decay and how do they work? Thanks!
April 24, 2009 by Lauren

Science
Need help with constructing a model of radioactive decay with popcorn kernals
March 20, 2011 by Kim

Science
3. What can scientists learn from the rate at which radioactive elements decay? (1 point)
November 6, 2013 by Nicole

Science
3. What can scientists learn from the rate at which radioactive elements decay? (1 point)
November 6, 2013 by Nicole

chemistry
You want to heat a satellite by radioactive decay of 238 plutonium. Assume you need heating of 200 Watts (J/s), how many Becquerel you need in your plutonium sample, if the decay energy of 238 plutonium is 5.593 MeV? (1 joule = 6.24 x 10^18 eV ) When will 1 mg of Pu be ...
November 19, 2010 by Anonymous

chem
Write a partial decay series for Rn-220 undergoing the following sequential decays: (alpha decay), , (beta decay), . (Enter the mass number in the first raised box, the atomic number in the second lower box and the symbol of the element in the third box. Enter the nuclide...
September 30, 2010 by lisa

math
An unknown radioactive element decays into non-radioactive substances. In 100 days the radioactivity of a sample decreases by 64 percent. a)(a) What is the half-life of the element? half-life: b)How long will it take for a sample of 100 mg to decay to 51 mg? time needed:
May 18, 2013 by Rachel

Problem
If an Elements has a half life of 20mins what is the radioactive decay of a 200gram sample?
June 11, 2013 by Half life

physics
The furthest distance from the Sun to Earth is df=1.521E8 The shortest distance from the Sun to Earth is ds=1.47E8 To simplify the problem, assume that the Earth's axis is always perpendicular to the plane of its trajectory around the Sun. The Sun always shines on half of the ...
June 9, 2013 by rishabh

Science
Radioactive substance decays so that after t years, the amount remaining, expressed as a percent of the original amount, is A(t)=100(1.6)^(-t). a) Determine the function A, which represent the rate of decay of the substance. b) what is the half-life for this substance? c) ...
March 6, 2012 by jessica

Geology
If the decay constant for radioactive decay of ^40 K is λ = 5.543*10^(-10) / year, use this equation to calculate ages of the samples in the following table: t(1/2) = 0.693/λ 1)What is the half life of 40K? table -----Np --- Nd---- Nd/Np A)6439-----2303---0.358 B)...
November 21, 2013 by Maura

Earth Science
Describe how Earth would be different today if. It contained no radioactive material. What would the consequences be for the Earth's interior layer?
September 30, 2009 by Breanna

Earth Science
Describe how Earth would be different today if it contained no radioactive material. What would the consequences be for the Earths interior layers?
December 2, 2010 by Jack

General chemistry
What is the decay constant for a radioactive isotope which decreases to 34% of its original value in 2.48 hours?
April 27, 2010 by me

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

earth
how Earth would be different today, if it contained no radioactive material
November 3, 2009 by Lizeth

science
Predicting Table of radioactive isotopes below Isotope type of decay Uranium-238 Alpha Nickel-63 Beta Iodine-131 Beta Radium-226 Alpha With the help of a periodic table, predict the element that forms in each case. Explain your reasoning.
May 4, 2014 by Andrean

Pre Calculus
Exponential Growth and Decay Find the half-life of a radioactive substance that decays by 5% in 9 years.
October 22, 2011 by Josh

Science
Identify and describe the type of radiation emitted during the radioactive decay of the radioisotope xenon 135
May 21, 2013 by Olivia

Geology
Does this sound right? Describe your assigned method and how it is used to evaluate geologic time. My assigned method was Absolute Dating / Numerical Age. Absolute Dating / Numerical Age is the process that assigns a numerical age ( this tells how old a rock or fossil is);to a...
March 31, 2009 by A.W.

science
Hello! I need help with some Science things. 1. Where is a good place to find a picture that describes radioactive decay, fussion and fission/ 4. Scientists use the amount of radioactive isotopes found in rocks and fossils to calculate their ages. This process is called_____ 5...
January 15, 2009 by Amy

advanced functions HELP!!!
Radioactive decay is the process by which an unstable element transforms into different element, typically releasing energy as it does so. For 500g of a radioactive substance with a half-life of 5.2 hours, the amount remaining is given by the formula M(t)=500(0.5) ^ t/5.2 a) ...
December 10, 2008 by james

geology / science
the age of granite can be determind using radiometric dating, explain the basis for the determination of a 238 U- Pb radiometric date of 1120 Ma for a granite. I have as the answer 238 U decays to Pb with an experimental law, that is the amount of U and Pb in granite are ...
April 18, 2007 by bex

Chemistry - radioactive decay .
list 2 reason why this isotope of gold- 191 would not be a good substitute for making jewelry?
September 18, 2012 by Maria

Physics
A radioactive substance decays from 2.0kg to 1.6kg in 156 days. How long would it take to decay to 1.1kg?
August 7, 2013 by Alice

physics
Explain with diagram the variation of the acceleration due to gravity (g) i) At a height h above the earth surface Inside the earth towards the centre of the earth. ii) What is the value of g at the centre of the earth. 2)Explain with example the term, damped harmonic motion 3...
July 30, 2008 by GoodMatrix

pre-calculus
Given that the radioactive decay equation is q = 1250 e-0.05t, if t is in months, the amount of milligram present after 4 year is?
March 4, 2012 by romain

Chem 2
The half-life for the radioactive decay of U-238 is 4.5 billion years and is independent of initial concentration. a) How long will it take for 10% of the U-238 atoms in a sample of U- 238 to decay? b)If a sample of U-238 initially contained 1.91018 atoms when the universe ...
July 21, 2011 by Kristina

Science
What process involves the comparison of rock layers with others in a sequence to determine its age? radioactive decay radiometric dating relative dating absolute dating To determine the most accurate and precise age of Earth's oldest rocks, geologists would use relative dating...
October 30, 2013 by Abby

Calculuc
How do you set up this problem? The decay constant for the radioactive element cesium 137 is .023 when time is measured in years. Find its half-life.
August 22, 2012 by Jillian

Astronomy
I have another question. What would an observer on the Moon looking at the Earth see? a) always see a fully-illuminated Earth b) always see a half-illuminated Earth c0 see phases of Earth d) see continuous darkness These are the four answers, but I would think it would depend ...
July 30, 2010 by PJ

chem
what changes in atomic number and mass number occur in a positron emmision of radioactive decay?
June 2, 2008 by jerson

math
A 10 kg quantity of a radioactive isotope decays to 3 kg after 17 years. Find the decay constant of the isotope.
February 3, 2011 by Eric

math
A 10 kg quantity of a radioactive isotope decays to 3 kg after 17 years. Find the decay constant of the isotope.
February 3, 2011 by Eric

math
A 10 kg quantity of a radioactive isotope decays to 3 kg after 17 years. Find the decay constant of the isotope.
February 3, 2011 by Eric

math
A 10 kg quantity of a radioactive isotope decays to 3 kg after 17 years. Find the decay constant of the isotope.
February 3, 2011 by Eric

math
A 10 kg quantity of a radioactive isotope decays to 3 kg after 17 years. Find the decay constant of the isotope.
February 3, 2011 by Eric

math
A 10 kg quantity of a radioactive isotope decays to 3 kg after 17 years. Find the decay constant of the isotope.
February 3, 2011 by Eric

math
A 10 kg quantity of a radioactive isotope decays to 3 kg after 17 years. Find the decay constant of the isotope.
February 3, 2011 by Eric

Physical Science
The heat of volcanoes and hot springs comes from trace amounts of radioactive minerals found in the Earth's interior. Why isn't the same rock at the Earth's surface warm?
March 10, 2008 by Rachel

Physical Science
3. Radioactive decay of nuclei often involves several decays before a stable nucleus is formed. This is called a decay chain. What stable isotope is formed when radon-222 undergoes a decay chain of four alpha decays followed by four beta decays? (A) tungsten-206 (B) platinum-...
November 20, 2013 by Adam

chemistry
a radioactive material is undergoing nuclear decay. After 40 minutes, 25% of the sample remains. What is the half-life of the sample
August 27, 2011 by marjani

Physics
A radioactive substance decays from 2.0kg to 1.6kg in 156 days. What is the decay constant and the half life of the substance?
August 6, 2013 by Alice

Chemistry
The nuclide 12 N 7 is unstable. What type of radioactive decay would be expected??? my guess is either gamma or beta. are either of those correct?
March 4, 2008 by Jonathan

math
The decay of 333 mg of a radioactive substance is given by A(t) = 333e-0.024t, where t is time in years. Find the amount left after 17 years.
April 8, 2011 by allison

science
I need a picture that describes radioactive decay, fussion and fision. Someone said that they would give me a link earlier but they didnt. Thank you! This website helps me out so much.
January 15, 2009 by Amy

chemistry
use logic and simple math to determine how long it will take for a sample of potassium- 42 to decay from 8mg to 0.25mg if the half-life of this radioactive isotope is 124 hours
October 12, 2010 by jay 1

Chemistry
Tc-99 is a radioactive isotope that decays by beta emission and is used by radiologists in the diagnosis of liver disease. Its decay behavior is shown by the activity-time table. What is its half-life?
December 10, 2011 by Jennifer

chemistry
I am having trouble understanding what the concept is for writing these out. Write a balanced nuclear equation for the alpha decay of each of the following radioactive isotopes: curium-243, 22589Ac
December 5, 2013 by ellie

physics
Radioactive decay of granite and other rocks in Earth's interior provides sufficient energy to keep the interior molten, to heat lava, and to provide warmth to natural hot springs. This is due to the average release of about 0.03 J per kilogram each year.Find an increase in ...
April 1, 2012 by christy

chemistry
Help plzzz Besides the major types of radioactive decay, there are two others: positron emission and electron capture. Compare and contrast positrons with electrons. Explain how positron emission works and how it causes transmutations. Explain how electron capture works ...
May 31, 2013 by Help!!! Maddie

math
if the rate for radioactive decay for a substance is r=-.0063 and time is being measured in days how do you find the half-life of the substance to the nearest hour?
March 30, 2009 by mike

Phyics Toughest question on earth
Estimate the time difference between the longest day and the shortest day of a year in seconds if you lived on the Earth's equator with the assumptions below. Note: this is not the difference between solstices as we are adjusting the earth's rotation axis to be in the orbital ...
June 4, 2013 by Mathslover

Earth Science
Earth is always changing. What are two forces that cause the earth's surface to constantly change and what are their effects on the planet? Please answer within a few minutes.
November 4, 2009 by Elizabeth

Pages: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | Next>>

Search
Members