Is shaking up salad dressing and sewing an apron a physical change?

Let's break down why shaking up salad dressing and sewing an apron are NOT physical changes:

* Shaking salad dressing: This is a physical change because it only alters the arrangement of the ingredients (mixing them) but doesn't change their chemical composition. The dressing is still made up of the same oil, vinegar, herbs, etc., just better combined.

* Sewing an apron: This is a physical change as well. You're altering the shape and form of the fabric, but you're not changing the chemical makeup of the fabric itself. The fibers are still the same, just arranged differently.

What is a physical change?

A physical change is a change in the form or appearance of a substance, but not its chemical composition. These changes are often reversible.

Examples of physical changes:

* Melting ice (water changes state from solid to liquid)

* Cutting paper (changes the shape of the paper)

* Dissolving sugar in water (sugar molecules are dispersed but not chemically altered)

What is a chemical change?

A chemical change results in the formation of a new substance with a different chemical composition. These changes are often irreversible.

Examples of chemical changes:

* Burning wood (wood reacts with oxygen to form ash, carbon dioxide, and water)

* Cooking an egg (the protein molecules in the egg change structure)

* Rusting metal (iron reacts with oxygen to form iron oxide)