en.wikipedia.org/wiki/Half-life

... of the following three equivalent **formulas**: ... is the **half**-**life** of the decaying
quantity, ...

www.coolmath.com/algebra/17-exponentials-logarithms/13-radioactive-decay-decibel-levels-01

Plutonium-239 has a **half**-**life** of 24,110 years. "**Half**-**life** means that, if you have
100 pounds of Plutonium-239... In 24,110 ... Here's one of the **formulas** they use:.

www.calculator.net/half-life-calculator.html

Free online tool to calculate any one of the values from the other three in a **half**-
**life formula** as well as to convert between half life, mean lifetime, and decay ...

www.softschools.com/formulas/chemistry/radioactive_halflife_formula/113

A radioactive **half**-**life** refers to the amount of time it takes for half of the original
isotope to decay. For example, if the **half**-**life** of a 50.0 gram sample is 3 years, ...

hyperphysics.phy-astr.gsu.edu/hbase/Nuclear/halfli2.html

The radioactive **half**-**life** for a given radioisotope is a measure of the tendency of
the nucleus to "decay" or ... so the standard form of the decay **equation** is: ...

www.chem.purdue.edu/gchelp/howtosolveit/Kinetics/Halflife.html

Equations for **half lives**; Determining a **half life**; Converting a **half life** to a rate ...
Substitute this information into the **equation** for the **half life** of a reaction with this ...

www.chemteam.info/Radioactivity/Radioactivity-Half-Life.html

Here is the first **equation**: (1/2)number of **half**-**lives** equals the decimal amount
remaining. Let us use several different **half**-**lives** to illustrate this **equation**. (1/2)^{0}
= ...