The question we were trying to answer is which changes are examples of a chemical change, and which are examples of a physical? we want to know how chemicals react and in what category they would fall in based on our observations. Conducted my investigation by combining chemicals and observing the reactions. I conducted my investigation this way because it would help me answer my question easily.
An example of chemical are the change in the coppers color, the reaction of sodium bicarbonate and hydrochloric acid, and the reaction of the 5 drops of sodium hydroxide and 5 drops of copper nitrate. An example of a physical change is the salt dissolving in water and the paraffin wax turning into a liquid when subjected to heat and cooling to a solid. These are all my evidence (observations)
1. The salt dissolved in water, the water became fogy.
2. The copper turned black when heated.
3. 5 drops of sodium hydroxide combined with 5 drops of copper nitrate turned into a solid.
4. 5 drops of hydrochloric acid added to 2 grams of sodium bicarbonate.
5. Paraffin wax was subjected to heat in hot water bath it turned into a clear liquid, when it cooled it turned into a solid color white.
These are my reasoning (because)
1. Physical change because the salt and water stayed but was in a different form.
2. Chemical change because it turned into something new the color tells us this .
3. Chemical because it turned into something we didn't have before.
4. Chemical because there was something that wasn't there before like the bubbles.
5. Physical change because the wax was the same but in a different form.
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