1 Metal like iron rust easily when exposed to chemicals. Why do iron rust? It is because it reacts with ______________ in the air.

2. If you leave an apple slice on the table for a couple of hours, which is likely to be observed?

3. If you cover a lighted candle with a glass jar, what will likely to occur?

4. Which will occur in the absence of oxygen?

5. Chemical reaction occurs in chemical change. Which show an evidence of a chemical reaction?

6. Physical change is a change in its size, shape, phase, form, texture and appearance but it still remains the same material. Which describe a physical change?

7. Chemical change is a change in its color, smell, or odor and the formation of bubbles. Which describe a chemical change?

8. Which is NOT an example of a chemical change?

9. Ash is a by-product of burning paper. Why do you think so?

10. In cooking leche flan, which steps show a chemical change?

11. Incineration is the destruction of waste materials through burning. Which is NOT an effect of incineration?

12. These are practices that we can do to prevent harmful effects of change in our environment. Which one is NOT?

13. People in a certain community throw garbage in the river. What do you think will happen the day after tomorrow?

14. Plastic products are durable, low cost, and easy to manufacture. What do you think happens if it is NOT disposed of properly?

15. Which activity contributes to polluting the environment?