Table of Contents
How many years is three half lives?
Q: If you had 1 gram of carbon-14, how many years would it take for radioactive decay to reduce it to 1/4 gram? A: 1 gram would decay to ¼ gram in 2 half-lives….Variation in Half-Lives.
| Isotope | Half-life |
|---|---|
| Uranium-238 | 4.47 billion years |
| Potassium-40 | 1.28 billion years |
| Carbon-14 | 5,700 years |
| Hydrogen-3 | 12.3 years |
How many years does 2 half-life of thorium have?
The time required for a radioactive substance to lose 50 percent of its radioactivity by decay is known as the half-life. The half-life of thorium- 232 is very long at about 14 billion years.
How much of an isotope remains after 3 half lives have passed?
Explanation: Three half lives corresponds to (12)3 . So a 18 quantity of the original isotope is retained.
How long does it take for thorium to decay?
14 billion years
The three long-lived nuclides are uranium-238 (half-life=4.5 billion years), uranium-235 (half-life=700 million years) and thorium-232 (half-life=14 billion years).
What is the half-life of 1.3 billion years?
Number of half-lives passed = total time elapsed / length of a half-life.
| Element | Parent Isotope | Half-life |
|---|---|---|
| Carbon | C-14 | 5,730 years |
| Potassium | K-40 | 1.3 billion years |
| Uranium | U-238 | 4.5 billion years |
| U-235 | 710 million years |
How many half lives does phosphorus have?
Phosphorus-32
| General | |
|---|---|
| Half-life | 14.268 days |
| Decay products | 32S |
| Isotope mass | 31.973907274 u |
| Excess energy | 24305 keV |
Does thorium-234 have a charge?
Alpha Decay In this nuclear change, the uranium atom (U23892) transmuted into an atom of thorium (Th23490) and, in the process, gave off an alpha particle. That means that the alpha particle has two protons in it which were lost by the uranium atom. The two protons also have a charge of +2.
What is the mass of thorium 230?
230.033
Th is a nuclide in the 238U decay series. It has a half-life of 7.54(2)×104 a, and is formed by α-decay of 234U….Thorium.
| Isotope | Atomic mass (Da) | Isotopic abundance (amount fraction) |
|---|---|---|
| 230Th | 230.033 132(8) | 0.0002(2) |
| 232Th | 232.038 05(1) | 0.9998(2) |
What percentage of a radioactive element will be left after 3 half-lives?
As you can see from this table, the amount of reactant left after n half-lives of a first-order reaction is (1/2)n times the initial concentration….Radioactive Decay Rates.
| Number of Half-Lives | Percentage of Reactant Remaining | |
|---|---|---|
| 2 | 50%2=25% | 12(12)(100%)=25% |
| 3 | 25%2=12.5% | 12(12)(12)(100%)=12.5% |
| n | 100%2n | (12)n(100%)=(12)n% |
How much radiation does thorium give off?
Thorium-232 (232Th) is present in significant amounts in the Earth’s crust and is an alpha-emitting radionuclide, which decays to radium-228 (228Ra), which is a beta emitter with a half-life of about six years; it emits no significant gamma radiation.
What is the longest half-life?
about 18 sextillion years
The half-life of xenon-124 — that is, the average time required for a group of xenon-124 atoms to diminish by half — is about 18 sextillion years (1.8 x 10^22 years), roughly 1 trillion times the current age of the universe. This marks the single longest half-life ever directly measured in a lab, Wittweg added.