1) A student observes bubbles when Sukang Iloko is poured on a limestone sidewalk and also when a pot of water boils for Pinakbet. Which statement correctly analyzes the difference? a) Both are chemical reactions because gas is being produced in the form of bubbles. b) b. Only the vinegar on the sidewalk is a chemical reaction because a new gas (CO2) is created, while boiling is just a physical change of state.Option 2 c) c. Both are physical changes because the bubbles eventually disappear into the air. 2) You are tasked with cleaning a tarnished silver spoon found in an old Vigan mansion. You decide to use a chemical "dip" that makes the spoon shiny again but produces a faint "rotten egg" smell. How does this apply to your knowledge of chemical evidence? a) No reaction occurred; the smell is just the cleaner's natural scent. b) It is a physical change because the spoon looks the same as it did when new. c) A chemical reaction occurred because the "rotten egg" smell indicates the production of a new gas as the tarnish is removed. 3) When mixing Apog (lime) with water for traditional mortar, the mixture gets very hot. If you were to graph this, what would it reveal about the atoms involved? a) The atoms are moving slower, which is why they release "extra" heat. b) The chemical bonds are breaking and reforming into a new substance, releasing energy in the process c) The water is simply boiling because the Apog acts like a tiny stove. 4) If you want to create a "Natural pH Testing Kit" for a local school using only Vigan flora, which design strategy shows the best use of chemical evidence? a) Boiling purple Kamote (sweet potato) to see if the water changes color when mixed with acidic Suka or basic Apog. b) b. Crushing green Malunggay leaves to see if they dissolve completely in water. c) Mixing salt and sugar together to see if they create a new color when added to vinegar.

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