## Half-Life

$\frac{d[R]}{dt}=-k[R]; \ln [R]=-kt + \ln [R]_{0}; t_{\frac{1}{2}}=\frac{0.693}{k}$

Linh Vo 2J
Posts: 61
Joined: Sat Apr 28, 2018 3:00 am

### Half-Life

When we talk about half-life, does this imply that there is normal life? I'm confused about what half-life is and when we would want to calculate it?

eden tefera 2B
Posts: 39
Joined: Fri Sep 28, 2018 12:21 am

### Re: Half-Life

Half life is the time that it takes for a substance to decompose into half of its intial state, no matter the state.

eden tefera 2B
Posts: 39
Joined: Fri Sep 28, 2018 12:21 am

### Re: Half-Life

To add, half-life is important to determine how quickly quickly unstable atoms undergo, or how long stable atoms survive, radioactive decay.

Rosha Mamita 2H
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Joined: Fri Sep 28, 2018 12:19 am

### Re: Half-Life

half life refers to the time it takes for a substance to decay by one-half of its initial amount. Half life and its equation are used to determine how old a substance is, the initial amount of a substance, or the final amount of a substance after a period of time

Cole Doolittle 2K
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### Re: Half-Life

Typically we would use the half-life formula to determine how long an element has been decaying.

Ashe Chen 2C
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### Re: Half-Life

In addition, half life is often used for carbon dating of samples, for example fossils, to determine from the amount of decay the sample has undergone. There is no normal life because that would imply that it is the time it takes for the entire sample to decay.

Yiting_Gong_4L
Posts: 69
Joined: Fri Sep 28, 2018 12:25 am

### Re: Half-Life

Half life is used to determine the time it takes for a substance to decompose into half its initial amount.

Brian Chang 2H
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Joined: Fri Sep 28, 2018 12:17 am

### Re: Half-Life

Linh Vo 2J wrote:When we talk about half-life, does this imply that there is normal life? I'm confused about what half-life is and when we would want to calculate it?

Half-life is defined as the time taken for the radioactivity of a specified isotope to fall to half its original value.

Simply put, it's the time taken for half of our sample to decay. ($\Delta t$ when x goes to x/2)