Which one among the following has the longest half-life?

Bismuth-209 (²⁰⁹Bi) is the isotope of bismuth with the longest known half-life of any radioisotope that undergoes α-decay (alpha decay).

What has the longest half-life?

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.

Which radioactive isotope has the longest half-life o15 or o19?

The rate constant for the decay of O-15 is less than that for O-19 . Therefore ,the rate of decay of O-15 will be slower and will have a longer half life .

Which among the following carbocations has longest half-life?

Triphenyl methyl carbocation is most stable because of maximum resonating structures (6) and aromaticity.

What is the longest known half-life of an isotope on Earth?

Answer and Explanation: The isotope with the longest known half-life is tellurium-128, with a half-life of 2.2 septillion years.

Which one among the following carbocations has longest half-life ?

Which has a longer half-life carbon-14 or uranium-238?

The half-life of the slightly unstable uranium-238 is 4.5 billion years. Carbon-14 has a half-life of 5,730 years.

Does carbon-14 have the longest half-life?

carbon-14, the longest-lived radioactive isotope of carbon, whose decay allows the accurate dating of archaeological artifacts.

What element in the series has the longest half-life?

The element that has the longest half-life is Bismuth. The isotope, Bismuth-209, goes through alpha decay every twenty billion billion years. Alpha decay is when alpha particles are emitted from the isotope.

Does more stable isotope have longer half-life?

Some isotopes that are classed as stable (i.e. no radioactivity has been observed for them) are predicted to have extremely long half-lives (sometimes as high as 10¹⁸ years or more).

Which one of the following unstable particle has the longest half-life?

Hence, the most unstable particle is the neutron with a half-life of only 10⁶ minutes.

Does uranium-238 have the longest half-life?

The U-238 isotope is the longest lived with a half-life of 4.5 billon years and constitutes more than 99% of the mass of natural uranium and half of its radioactivity.

What is the longest half-life of radioactive waste?

Iodine-129 has the longest half-life, 15.7 million years, and due to its higher half life, lower fission fraction and decay energy it produces only about 1% the intensity of radioactivity as ⁹⁹Tc.

What is the longest lived isotopes?

With a half-life of 81 million years, plutonium-244, the longest-lived plutonium (Pu) isotope, can be produced both naturally and by anthropogenic means.

What makes a longer half-life?

Half-life is dependent on both clearance and volume of distribution, such that a decrease in clearance, as might be seen with a CYP1A2 or CYP2C19 substrate, or an increase in volume of distribution will prolong the half-life and lead to a longer dosage interval.

What has the longest and shortest half-lives?

The longest-lived isotope of lawrencium, ²⁶²Lr, has a half-life of 3.6 h, while the shortest-lived isotope of lawrencium, ²⁵²Lr, has a half-life of 0.36 s. As of this writing, the largest atom ever detected has atomic number 118, mass number 293, and a half-life of 120 ns.

What is an example of long half-life?

However, there are numerous other drugs with very long half-life, examples are mefloquine 14–41 days (25), amiodarone 21–78 days (26), and oritavancin 393 h (27). Furthermore, what can be called “long half-life” is always relative to the length of the sampling period.

What are the half-lives of two longest-lived radioactive isotopes?

The longest-lived radioactive isotopes are ³³P with a half-life of 25.34 days and ³²P with a half-life of 14.268 days. All others have half-lives of under 2.5 minutes, most under a second.

Which isotope has shortest half-life?

You may wonder which naturally-occurring element has the shortest half-life. That would be francium, element 87, whose longest-lived isotope, francium-223, has a half-life of 22 minutes, decaying either into radium by beta decay or astatine by alpha emission.

Do radioisotopes have long half-lives?

The radioisotopes used for imaging and treatment in medical sciences are usually synthesized and have a short half-life so that they may not persist in the body for an unnecessarily long time.

What element has a half-life?

Uranium-232 has a half-life of about 69 years. Plutonium-238 has a half-life of 88 years. Carbon-14, which is used to find the age of recent fossils, has a half-life of 5,730 years.

Does carbon have a long half-life?

C has a half-life of 5,730 years. In other words, after 5,730 years, only half of the original amount of ¹⁴C remains in a sample of organic material.

Does carbon 13 have a half-life?

Radioactive decay

Its half life t is 5730 years, i.e., somewhat larger than the half life determined by Libby (5568 ys).

Does carbon-14 have a longer half-life than potassium-40?

Carbon-14 has a longer half-life than potassium-40. Once a living thing dies, it no longer takes in carbon. Carbon-14 dating is used to date very old volcanic rock. Carbon-14 dating works for fossils as old as 50,000 years.

How long can carbon-14 live?

It is then incorporated into all living organisms by means of the food chain. After an organism dies, its level of carbon-14 gradually declines at a predictable pace, with a half-life of about 5,730 years. Archaeologists precisely measure levels of the isotope in organic remains.

Is carbon-14 a radioactive and has a half-life of 5 700 years?

Radioactive Dating

For example, carbon-14 has a half-life of 5,730 years and is used to measure the age of organic material. The ratio of carbon-14 to carbon-12 in living things remains constant while the organism is alive because fresh carbon-14 is entering the organism whenever it consumes nutrients.