Classify the following into physical and chemical changes.
(a) Expansion of metals on heating
(b) Crystallization of salts from their solutions.
(c ) Blackening of silverware
(d) Ripening of fruits
(e) Cooking of food
(f) Melting of ice

Explanation

To classify the given changes into physical and chemical changes, we need to understand the definitions of each type of change:

1. **Physical Change**: A change that does not alter the chemical composition of a substance. These changes are usually reversible.
2. **Chemical Change**: A change that results in the formation of new chemical substances. These changes are usually irreversible.

Now, let's classify each of the given changes step by step:

### Step-by-Step Solution:
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