What is half-life of a radioactive substance?

What is half-life of a radioactive substance?

half-life, in radioactivity, the interval of time required for one-half of the atomic nuclei of a radioactive sample to decay (change spontaneously into other nuclear species by emitting particles and energy), or, equivalently, the time interval required for the number of disintegrations per second of a radioactive …

What is the half-life of the substance?

In a chemical reaction, the half-life of a species is the time it takes for the concentration of that substance to fall to half of its initial value. In a first-order reaction the half-life of the reactant is ln(2)/λ, where λ is the reaction rate constant.

How do you calculate the half-life of a radioactive substance?

The time taken for half of the original population of radioactive atoms to decay is called the half-life. This relationship between half-life, the time period, t1/2, and the decay constant λ is given by t12=0.693λ t 1 2 = 0.693 λ .

What is the half-life of a radioactive substance if 75?

What is the half-life of a radioactive substance if 75% of a given amount of the substance disintegrates in 30 minutes? Solution: 75% of the substance disintegrates in two half lives. ∴ t1/2=15min.

What is the half-life of a radioactive isotope quizlet?

Terms in this set (20) Half life is the time it takes for the number of nuclei in a radioactive isotope in a sample to halve.

What is the half-life of uranium 234?

about 25 thousand years
The half-life of uranium-238 is about 4.5 billion years, uranium-235 about 700 million years, and uranium-234 about 25 thousand years.

What is the half-life of a radioactive substance if 75% of its given amount disintegrates in 60 min?

Half life of a radioactive substance which disintegrates by 75% in 60 min be. 75% of the substance disintegrates in two half lives.

What nuclear decay makes sodium 24 stable?

beta decay
Figure 7: Decay scheme of a radioactive sodium-24 (24Na) nucleus. With a half-life of 15 hours, it decays by beta decay to an excited magnesium-24 (24Mg) nucleus. Two gamma rays are rapidly emitted and the excitation energy is carried off, whereby the stable ground state of magnesium-24 is reached.

Does the half-life of a radioactive isotope change?

Yes, the decay half-life of a radioactive material can be changed. Radioactive decay happens when an unstable atomic nucleus spontaneously changes to a lower-energy state and spits out a bit of radiation. This process changes the atom to a different element or a different isotope.

What is the half life of a radioactive substance?

The half-life of a radioactive substance is a characteristic constant. It measures the time it takes for a given amount of the substance to become reduced by half as a consequence of decay, and therefore, the emission of radiation.

What does 10 days mean in radioactive terms?

Ten days means the substance is intensely radioactive; if it is present in an amount more than a dust mote, it will prove harsh on life close to it, though it decays fairly quickly.

Which is an example of a radioactive substance?

Let’s look at some different uses of radioactive substances. Nuclear power plants. One example of a radioactive substance is uranium. In nuclear power plants, uranium is used to produce electricity. When radioactive substances like uranium produce radiation, they also create a lot of heat.

How is the mean life of an atom determined?

Some atoms have short life time while others have longer. Thus making the life of every atom different.Therefore it is useful to determine the mean life of the radioactive substance. The mean life is hence determined by the ratio of the Total life of all the atoms to the Number of atoms present in the radioactive substance.