# Question #2720a

##### 1 Answer

Decay constant:

#### Explanation:

If the **half-life** is 3000 years, we can say that the amount of activity follows this rule:

So for

This is the most literal formulation of the idea of a **half-life** .

The **decay constant** is slightly more abstract, it requires us to move to using natural logs:

So we have now calculus-friendly exponential decay.

We can then say that:

Or:

So we test this again using our new definition: