Explanation:
This task is about identifying which processes are examples of
chemical change — a change where new substances are formed, and the change usually cannot be easily undone.
Let’s go through each option one by one:
1.
Cooking – When you cook food (like baking bread or frying an egg), the ingredients undergo chemical reactions (e.g., proteins denature, Maillard reaction). This is a
chemical change.
2.
Dissolving – When sugar dissolves in water, it’s still sugar — just spread out. No new substance forms, and you can get the sugar back by evaporating the water. So this is a
physical change, *not* chemical.
3.
Can’t be reversed – This is a *property* of many chemical changes (though not all — some *can* be reversed with effort), but it’s not itself a process. We’re looking for actual processes, so this is not a correct answer choice as a process.
4.
Can be reversed – Same issue: this describes reversibility, not a process. Not a valid answer here.
5.
Ice cube melting – Solid water turns to liquid water. Same substance (H₂O), just state change. That’s a
physical change.
6.
Frying an egg – The heat causes the egg proteins to change structure permanently (they coagulate). You can’t “unfry” an egg — new substances form. This is a
chemical change.
7.
Burning wood – Wood reacts with oxygen to produce ash, smoke, CO₂, etc. New substances form →
chemical change.
8.
Chopping wood – Just cutting wood into smaller pieces. Still wood. No new substance →
physical change.
Now, look at the central figure: it has a label pointing to it that says
“Chemical Change”, and it's surrounded by the listed processes. The goal is to identify which ones belong in the “chemical change” group.
From above, the true chemical changes are:
- Cooking
- Frying an egg
- Burning wood
Note: While “can’t be reversed” is often *associated* with chemical changes, it’s not a process — it’s a description. The question asks for processes (like actions), so we only pick the action words.
Final Answer:
cooking, frying an egg, burning wood
Parent Tip: Review the logic above to help your child master the concept of chemical change worksheet.
