Isotope Definition and 107 Threads

first, is my initial understanding correct that each isotope go for only a particular kind of decay? and if so, why? What makes uranium-238 go only for an alpha decay? while uranium 235 go for a fission decay?

Homework Statement I'm really confused about this concept. I know that when you evaporate a liquid, heavier isotopes stay behind because it's easier to evaporate lighter isotopes. This is intuitive to me. I'm confused on the case of condensation because I'm reading two things that seem...

Homework Statement The half life of a particular isotope is 10.84 days. Find the number of atoms of this isotope that would be necessary to produce a sample with an activity of 1.79 micro-Ci. Homework Equations R=N_{0} \lambda e^{-\lambda t} where R is the decay rate lambda is the decay...

Homework Statement A radioactive sample contains 2.25g of an isotope with a half-life of 3.8 days. How much of the isotope in grams will remain after 11.0 days? Homework Equations The Attempt at a Solution Hi! I've just started college this semester. I'm taking Introductory Chemistry. Right...

Let's say there a particular hydrogen atom would be a rare-occuring hydrogen atom without a nuetron. And let's say it's a cation that donated it's electron. Would it essentially be just a wandering proton?

Homework Statement The isotope 239Pu has a half-life of 24,100 years. After 10,000 years, a sample of the isotope is reduced 1.6 grams. What was the intial size of the same (in grams)? How large was the sample after the first 1,000 years. Round your answer to four decimal places.Homework...

Hi I am looking for ion density an ion mass of Boron 10, the particle of BF3 but I could not figure out these 2 number yet. I really need them to calculate the frequency of the particle isotope. any help would be appreciated.

I need to complete the following sentence. If I think that electron capture or alpha decay does not occur in my decay process, I have to type a '0' (zero) in the appropriate box: Converting an atom of the isotope Uranium (238-92) into an atom of thorium can be accomplished if an electron...

In some threads around here I have hinted to problems with the use of 'water' isotope ratio's (δ18O, δ2H aka δD) as thermometer of past temperatures. This could become a dense thread, so I'll give the conclusion first: The isotope ratio's in ice cores and other records of meteoric water are...

New here, guys. I anterospectively appreciate your patience with me. I am neither a professional physicist nor even a student (at least not formally) of physics. However, after some perusing I just now understand the rudiments of special and, I think, general relativity. And, like a child...

On the part “(0.8022 x 11.009) + (0.1978 x W) = 10.81 amu (natural atomic weight),” how do I know what to multiply 0.1978 by if W is unknown? How did they arrive at 10.81?

Homework Statement The present day value of the uranium isotopic ratio U-235/U-238 is 0.00723. The half life of U-238 is 4.51 x 10^9 and the half life of U-235 is 7.13 x 10^8 years. What was the U-235/U-238 isotopic ratio 2 billion years ago when the Oklo natural reactor was active...

Hi People! The half-lives of elements seem to follow some rules of thumbs, but the exact or even order of magnitude for most cases it seem quite random. So, is there any numerical method to figure that out?

Homework Statement The polonium isotope 210Po, an alpha emitter, has a half-life of 138.38 days. You happen to have a 1.5 g cube of 210Po, so you decide to use it to boil water for tea. You fill a well-insulated container with 120 mL of water at 18° C and drop in the cube of polonium. (a)...

Hi, just learning about alpha and beta particles in class this week. What does it mean that the nucleus is unstable in a radioactive isotope? Is this a condition that must be present for nuclear radiation?

Homework Statement Why is it important in brachytherapy to realize that rhodium is not a stable isotope? If rhodium were not a stable isotope, what considerations must one make? I know that a stable isotope can go from one element to another, but I don't see how that would have anything to...

Heres the question [PLAIN]http://img213.imageshack.us/img213/2669/16772870.jpg I know that I'm supposed to derive these values from the fact that I know the absorptions of 2 different isotopes of the diatomic molecule but I don't know how to go about doing it. I can obtain the masses of...

We are taught that the three basic types of radioactive particles are alpha, beta, and gamma. I know there are other particles, but for now I'm just focusing on these. Alpha particles don't penetrate skin, beta particles do and can cause burns, and gamma rays are very powerful. But my chem...

First off I just wanted to say something quickly. I am a Visual Arts major taking a Introductory Physics class for fun, (probably my favorite class that I have ever taken, also the most rewarding. I have learned so much that I wish I had taken it sooner so I could have pursued it more) My...

I understand half-lives, how various atoms decay through the various types of emissions (alpha, beta, gamma, etc). It's easy to do the math (or read the decay chain) for various things to see what the end-stable result if (eg U-238 and 235 decay to a thorium isotope, eventually to lead)...

Hello! i was just wondering if anyone could help me with this, The rubidium isotope 87-Rb is a beta emitter with a half life of 4.9 x 10^10 yr that decays into 87-Sr. It is used to determine the age of rocks and fossils. Certain rocks contain a ratio of 87-Sr to 87Rb of 0.0100. Assuming there...

Homework Statement Like, if you are writing out one of the blocks on the table of elements chart, you would write out the letter of the element, and then you would write the atomic average (or atamoic mass it is also known as,) on the bottom left , and the atmomic mass on the top to the...

Q: The actual mass of one atom of an unknown isotope is 2.18 x 10^-22g. Calculate the atomic mass of this isotope. `How do I calculate it? help =]

Homework Statement Carbon has two naturally occurring isotopes with the following isotopic masses: 12 (exactly) and 13.003. Calculate the percent natural abundance of carbon-13. Homework Equations I'm not sure if this is right, but here's what I used. I set up a system of two...

So this is a very novice but sincere question. I've just done a bit of reading about Bose-Einstein condensates, and the question that I immediately had was, What happens if one creates a BEC out of an isotope which is subject to radioactive decay? Would the atoms all necessarily remain in the...

only one isotope of element X occurs in nature. One atom of this isotope has a mass of 9.123x10-23g. What is the molar of the element X?

Canada is currently the largest supplier of the world's radioactive medical isotopes. That is until AECL's aging NRU reactor at Chalk River sprang a leak and had to be shut down. AECL had built two reactors in the 1990's, Maple I and II, to produce medical isotopes but due to design problems...

Homework Statement There are three main isotopes of carbon, with the following atomic masses: Atomic Masses 12^C 1.99 x 10^-26 kg 13^C 2.16 x 10^-26 kg 14^C 2.33 x 10^-26 kg The atoms of carbon are singly ionized and enter a mass spectrometer with magnetic field strength B = 0.200 T at...

Homework Statement A particular isotope of dysprosium has atomic number 66 and atomic mass 159.952202 u. Identify the nucleus with a radius that is one half that of this isotope. A. Ne (A=20, Z=10) <<<Correct Answer B. O (A=16, Z=8) C. Mn (A=50, Z=25) D. Ni (A=60, Z=28) Homework...

1. Homework Statement The relative abundance of uranium isotopes in today’s Earth crustal material is: 99.2745% 238U 0.7196% 235U 0.0055% 234U What were the relative abundances when the Earth was formed 4.6x109 years ago? 2. Homework Equations t = age = 1/lambda * ln(N/No) N...

Homework Statement The relative abundance of uranium isotopes in today’s Earth crustal material is: 99.2745% 238U 0.7196% 235U 0.0055% 234U What were the relative abundances when the Earth was formed 4.6x109 years ago? Homework Equations t = age = 1/lambda * ln(N/No) N =...

Homework Statement Natural carbon consists of two different isotopes (excluding 14C, which is present in only trace amounts). The isotopes have different masses, which is due to different numbers of neutrons in the nucleus; however, the number of protons in the same, and subsequently the...

Homework Statement A sample of radioactive isotopes contains two different nuclides, labeled A and B. Initially, the sample composition is 1:1, i.e., the same number of nuclei A as nuclei B. The half-life of A is 2 hours and, that of B, 4 hours. What is the expected ratio A/B after 8 hours...

Homework Statement Homework Equations why there is no isotope of hydrogen with an atomic weight of four? The Attempt at a Solution i find that such an isotope would have an isotopic spin state of 1/2 |2-1> + 3/2 |1 -1> is there a reason for this state to not exist?

Homework Statement Measurements of a certain isotope tell you that the decay rate decreases from 8337 decays/minute to 3174 decays/minute over a period of 5.00 days. Homework Equations R=Ro.e^-lamda/t then T1/2 = ln(2)/lamda The Attempt at a Solution I converted all the units...

hello, new & amazed by all the knowledge and passion on these forums..wow! well no questions are stupid i hope. I've been looking into basic radioactivity lately and it has led me to some question marks about isotopes' stability. The isotopes in question are ^{108}Ag and ^{110}Ag with the half...

Hi i got a short question if i know the following U238 decays spontaniously to 2 Neutrons and Tellurium136 and some other isotope. How can i tell what other isotop is produced. Sure i know about baryon number conservation lepton number conservation can i just say ok i got 238 baryons on...

If the rate of an isotope in 18 days has dropped by one eight of its initial value. what is the half life of the isotope? My answer In 18 days the rate has dropped by 1/8 so therefore the half life is 4/8 which is 18*4 = 72days

My teacher said that if an isotope has a neutron to proton ratio that is greater than 1.2 it is radio active, but he said there is one exception when the ratio is lower than 1.2 .. something about the isotope being synthetic. Can someone help me an explain exactly what this exception is...

From what I gather a hydrogen bomb works by exploding a conventional explosive such as TNT which propells fissile Uranium or Plutonium particles at each other which causes fission and this fission causes enough heat to start fusion. Then I hear lithium is bombarded with by an electrons which...

Homework Statement One of the many isotopes used in cancer treatment is 19879Au, with a half-life of 2.70 d. Determine the mass of this isotope that is required to give an activity of 200 Ci. Homework Equations 200Ci x 3.7x10^10 decays/s = 7.4 x 10^12 decays/s T1/2 = ln2/lambda =...

Deuterium is heavier then Hydrogen so a metal bonded to H vs. C can be determined by isotopic exchange and then using Infrared Spectroscopy/mass spec. But how do you replace hydrogen with deuterium? a.Dehydrogenation and then add deuterated solvents (heavy water or CDCl3 ..deuterated...

Can somebody please help me with this problem? i Would really appreciate it.:smile: 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.

i have been given an equation of, delta(N) = N(t).delta(t)/T where N(t) is the number of atoms left at time t, and T is the half life. Using a constant time and variable half lifes i have to come up with a formula to calculate the remaining atoms left over. the formula i was able to...

My question relates to calculating the decay lifetime of an unstable isotope. The information given is the average energy of the emitted gamma ray from the decay has an average energy of say 100kev and a line-width of 5 x 10^-6ev. From this information I need to work out the average lifetime for...

Hello All, I would like to know how would I go about determining the half life of an isotope when this infoormation is give to me: Time (hr) Mass Remaining of the Isotope (g) 0.0 40.00 3.0 20.00 6.0 10.00 9.0 5.00 12.0 2.50 15.0...

I'm trying to find the mass of a given isotope in terms of amu. The isotope is ^{210}_{84} Po , which has a mass of 209.98285u. I've tried 84(1.007276u) + 126(1.008665u) thinking that #protons(proton mass in amu) + #neutrons(neutron mass in amu) = mass in amu, give or take. Can anyone help?

Is it possible to identify such an isotope? What are my choices if I wanted such a long half-life product. (Ultimately, I need it to activate a timing switch...!) :smile: Thanks, anyone for any pointers. AA

How would you go about to solve this quesiton? I thought that to calculate this i had to set up an equation as: let x = the percentage of 85-Rb 84.91*x + 86.91*(1-x) = 85 x = 96%, but that's obviously wrong. How do i solve this question?

The half-life of carbon-14 is 5730 years. If a sample had 26 g of carbon-14, how much would it contain after 22,920 years (x 4)?