For a radioative substance, write the relation between:
Mean life `(tau)` and disintegration constant `(lamda)`

Explanation

To find the relation between the mean life (τ) and the disintegration constant (λ) for a radioactive substance, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Definitions**:
- The **mean life (τ)** of a radioactive substance is the average time that a nucleus of the substance will exist before it decays.
- The **disintegration constant (λ)** is a probability rate at which a nucleus will decay per unit time.

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