Áireamhán Leathshaoil
Lobhadh radaighníomhach: faigh an méid atá fágtha, an t-am atá caite nó an leath-shaol, le cuar lobhadh.
Torthaí a nuashonrú mar a chlóscríobh tú.
Maidir leis an áireamhán seo
The half-life is the time it takes for half of a radioactive sample to decay, and it sets the pace of the whole process through N = N₀ × (½)^(t / t½), where N₀ is the starting amount, t is the elapsed time and t½ is the half-life. After one half-life half the material remains, after two a quarter, after three an eighth, and so on — the amount never quite reaches zero but halves with every t½ that passes. Choose what to solve for: the amount left after a given time, the time needed to fall to a given amount, or the half-life itself inferred from a measured decay.
As a worked example, carbon-14 has a half-life of 5,730 years, so a sample that starts with 100 units of C-14 falls to 100 × (½)^(2000 / 5730) ≈ 78.5 units after 2,000 years. The calculator also reports the decay constant λ = ln2 / t½ ≈ 0.693 / t½ (the probability a given atom decays per unit time) and the mean lifetime τ = 1 / λ = t½ / ln2, which is about 1.44 half-lives — the average time an individual atom survives — and plots the decay curve.
Because the maths is scale-free, the time and the half-life only need to share the same unit — years, days, seconds or hours — and the initial and remaining amounts can be in grams, atom counts, becquerels or any consistent measure. This makes the tool equally at home with radiocarbon and radiometric dating, medical isotope dosing, nuclear-waste decay planning and any first-order exponential decay, including some drug-elimination and discharge problems that follow the same half-life mathematics.
Ceisteanna Coitianta
Cad é an fhoirmle meath leath-saoil?
Is é an méid atá fágtha tar éis am t ná N = N₀ × (½)^(t/t½) Tar éis leathré amháin tá leath fágtha, tar éis dhá leathré ceathrú, tar éis trí ochtú, agus mar sin de.
Cad é an tairiseach meath agus meánshaol?
Is é an tairiseach meath ná λ = ln2 / t½ ≈ 0.693 / t½, an dóchúlacht meath in aghaidh an aonaid ama. Is é an meánshaol τ = 1 / λ = t½ / ln2 an meán-am a mhaireann adamh - thart ar 1.44 leath-shaol.
An féidir liom an leath-shaol a fháil ó dhá thomhas?
Socraigh "solve for" go leath- shaol agus cuir isteach an méid tosaigh agus an méid atá fágtha móide an t- am atá caite; réitíonn an uirlis t½ = t × ln2 / ln( N₀/ N).
Cén chaoi a bhfuil carbóin-14 ag dul in aois a bhaineann le leathré?
Tá leathré 5,730 bliain ag carbón-14, agus dá bhrí sin, is féidir an méid carbóin-14 atá fágtha i sampla a thomhas. Ó 100 aonad, tá thart ar 78.5 aonad fágtha tar éis 2,000 bliain. Tá thart ar leath na n-aonad fágtha tar éis 5,730 bliain.
Cén aonaid a úsáideann an t-am agus an leath-shaol?
Aon aonad, chomh fada agus a roinneann an t- am caite agus an leathshaol é. Iontráil iad araon i mblianta, nó iad araon i soicindí; is é an cóimheas t / t½ an t- ábhar go léir, agus tagann na torthaí ar ais san aonad céanna.
Cé mhéad atá fágtha tar éis roinnt leath-shaol?
Iolrú faoi leath amháin do gach leath-saol: 50% tar éis ceann, 25% tar éis dhá, 12.5% tar éis trí, 6.25% tar éis ceithre.Tar éis deich leath-saol faoi 0.1% fós, agus sin an fáth go bhfuil "thart ar deich leath-saol" riail choitianta le haghaidh éifeachtach imithe.
An bhfuil leath-saol ag brath ar cé mhéad ábhar a thosaíonn mé le?
Is maoin sheasta í an iseatóp, neamhspleách ar mhéid an tsampla, ar theocht nó ar staid cheimiceach. Cibé an dtosaíonn tú le gram nó le tonna, meathfaidh leath i leathré amháin go díreach — agus is é sin a dhéanann clog iontaofa den sórt sin.
API — úsáid an áireamhán seo ó chód
Glaoigh ar an áireamhán seo mar chríochphointe JSON saor in aisce - níl aon eochair ag teastáil. Seol na luachanna réimse thíos mar pharaiméadair cheist nó JSON. Anything you omit uses the same default this page is pre-filled with; an unknown parameter is a 400, never a silent zero. Léigh an doiciméadú iomlán API →
Deireadhphointe
GET https://calculator.free/api/v1/half-life/curl
curl "https://calculator.free/api/v1/half-life/?solve=remaining&initial=100&half_life=5730&time=2000"JavaScript fetch()
const r = await fetch(
"https://calculator.free/api/v1/half-life/?" + new URLSearchParams({
"solve": "remaining",
"initial": "100",
"half_life": "5730",
"time": "2000"
}));
const data = await r.json();
console.log(data.results);Is meastacháin iad na torthaí le haghaidh treoir ghinearálta amháin, ní comhairle airgeadais, leighis nó cánach.