Question

3 cutting a piece of aluminum foil
4 rust forming on a bike chain
5 mixing vinegar and baking soda (bubbles form)
6 boiling water to make steam
7 an egg cooking in a frying pan
8 sugar dissolving in water
9 a banana turning brown
10 breaking a glass bottle

part 4: short answer

1. what is one way to tell a chemical change has occurred?

1. why is melting ice considered a physical change?

1. describe one chemical change youve seen at home or in nature.

Explanation:

Part 4: Short Answer

1.

A chemical change produces new substances. Indicators include color change, gas production (bubbles), precipitate formation, energy change (heat/light), or odor change. For example, gas bubbles (like in vinegar + baking soda) show a new substance (CO₂) is made.

Melting ice changes water from solid to liquid, but the substance (H₂O) remains the same. No new substance is formed, so it’s a physical change (change in state, reversible, no chemical bonds broken/formed).

A chemical change at home: baking bread. Yeast ferments sugars, producing CO₂ (gas) and alcohol, causing dough to rise. New substances (CO₂, alcohol) form, and the bread’s texture/taste change irreversibly.

Answer:

One way is the formation of a new substance, indicated by signs like gas bubbles (e.g., from mixing vinegar and baking soda), color change, or a precipitate forming.

2.