What is the amount of substance remaining after 6 days?
What is the amount of substance remaining after 6 days?
11.2: Half-Life
| Isotope | Life |
|---|---|
| 131I | 8.04 d |
| 222Rn | 3.823 d |
| 235U | 7.04 × 108 y |
| 238U | 4.47 × 109 y |
How do you calculate the half life of a radioactive substance?
Half Life Formula
- t12 t 1 2 = half-life.
- Given decay constant λ = 0.84. The half life formula can be used to find the half life of the substance. t12 t 1 2 = 0.693/λ
- Solution: Given half life of the substance is t12 t 1 2 = 0.04. The half life formula can be used to find the half life of the substance.
- t12 t 1 2 = 0.693/λ
How do you calculate half life and decay constant?
The time required for half of the original population of radioactive atoms to decay is called the half-life. The relationship between the half-life, T1/2, and the decay constant is given by T1/2 = 0.693/λ. The Editors of Encyclopaedia BritannicaThis article was most recently revised and updated by Erik Gregersen.
How do you find the half life of a specific activity?
To find the activity R using the equation R=0.693Nt1/2 R = 0.693 N t 1 / 2 , we must know N and t1/2. The half-life of 14C can be found in Appendix B, and was stated above as 5730 y. To find N, we first find the number of 12C nuclei in 1.00 kg of carbon using the concept of a mole.
How many days is a half-life?
You know that the half-life of a radioactive nuclide, t1/2 , tells you the time needed for half of the atoms present in a sample to undergo radioactive decay. In this case, it takes 3.6 days for any sample of this substance to decay to half of its initial mass.
What’s the half-life of carbon 14?
5,730 ± 40 years
Carbon-14 has a half-life of 5,730 ± 40 years—i.e., half the amount of the radioisotope present at any given time will undergo spontaneous disintegration during the succeeding 5,730 years.
What is the half-life of a radioactive isotope?
Radioactive half-life is the time required for a quantity of a radioisotope to decay by half. If the half-life of an isotope is relatively short, e.g. a few hours, most of the radioactivity will be gone in a few days.