Potassium-40 is a rare example of an isotope that undergoes both types of beta decay. In about 89.28% of events, it decays to calcium-40 ( 40 Ca) with emission of a beta particle (β − , an electron) with a maximum energy of 1.31 MeV and an antineutrino.
What does potassium-40 break down to?
The half-life of potassium-40 is 1.3 billion years, and it decays to calcium-40 by emitting a beta particle with no attendant gamma radiation (89% of the time) and to the gas argon-40 by electron capture with emission of an energetic gamma ray (11% of the time).
What is the equation for potassium-40?
Potassium- 40 is an interesting isotope of potassium, that can undergo both beta-plus and beta-minus decay. It has an 89% chance of undergoing beta-minus decay, turning into calcium- 40 , and the equation for that is: 4019K→4020Ca+e−+ ̄v , where ̄v is an antineutrino, and e− is an electron.
Where does potassium-40 come from?
Potassium-40 (40K) is a naturally occurring radioactive isotope of the common element potassium (potassium represents about 2.4% by weight of the earth's crust). The half-life of 40K is 1.248 x 109 years [1] its origins are primordial. 40K has an atomic percent abundance of 0.0117%.
What is the daughter isotope of potassium 40 decay?
Potassium-40 is a radioactive isotope that has a half-life of 1.25 billion years. The daughter isotope of potassium-40 is argon-40 .
What material is the best application for potassium-40?
The very slow decay of potassium 40 into argon are highly useful for dating rocks, such as lava, whose age is between a million and a billion years. The decay of potassium into argon produces a gaseous atom which is trapped at the time of the crystallization of lava.
Which shows the decay of potassium-40?
In about 89.28% of events, it decays to calcium-40 ( 40 Ca) with emission of a beta particle (β − , an electron) with a maximum energy of 1.31 MeV and an antineutrino. In about 10.72% of events, it decays to argon-40 ( 40 Ar) by electron capture (EC), with the emission of a neutrino and then a 1.460 MeV gamma ray.
How long does it take half of potassium-40 to decay?
The half-life of potassium-40 that decays through beta emission is 1.28 × 10 9 years , however the half-life of potassium-40 that decays through positron emission is 1.19 × 10 10 years.
Is potassium-40 a gas?
...the rare, naturally radioactive isotope potassium-40. The gas slowly leaks into the atmosphere from the rocks in which it is still being formed.
What is the half-life of potassium-40 quizlet?
The half-life of Potassium-40 is 1.3 billion years .
How long will it take potassium-40 to reduce by 50%?
Half-life (t1⁄2) is the amount of time required for a quantity to fall to half its value as measured at the beginning of the time period. After 1300 million years ( first half life) 200 /2 = 100 g decays and 100 g remains left.
What percentage of potassium is radioactive?
Potassium (K) is a widely encountered element with a very small fraction of its atoms, about 0.012% , being radioactive. These K-40 atoms spontaneously decay, releasing electrons (beta radiation) as well as gamma rays.
Is calcium 40 stable or unstable?
Calcium 40 Carbonate (Calcium-40) is a stable (non-radioactive) isotope of Calcium. It is both naturally occurring and produced by fission.
Are bananas radioactive?
Bananas are slightly radioactive because they are rich in potassium, and one of its natural isotopes (variants) is potassium-40, which is radioactive.
Why is potassium-40 useful for dating very old rocks?
Geologists have used this method to date rocks as much as 4 billion years old. It is based on the fact that some of the radioactive isotope of Potassium, Potassium-40 (K-40) ,decays to the gas Argon as Argon-40 (Ar-40) . ... For every 100 K-40 atoms that decay, 11 become Ar-40.
What material is the best application for potassium?
Agricultural use
Potassium chloride is the most widely applied K fertilizer because of its relatively low cost and because it includes more K than most other sources: 50 to 52 percent K (60 to 63 percent K2O) and 45 to 47 percent Cl−. More than 90 percent of global potash production goes into plant nutrition.
