In this activity, several changes will be made to samples of matter. your challenge will be to decide if the change is physical or chemical. you will also have to defend your choice. remember that when a physical change occurs to a substance, the identity of the substance and its physical properties do not change. however, when a chemical change occurs to a sample, the original material is converted to a new form of matter. this substance has a unique set of physical and chemical properties.

write a summary paragraph discussing this experiment and the results. use the following questions to guide the content of your paragraph.

submit your recorded observations for each step.
step 1: burning candle - record the mass and write your observations

step 2: cooling candle - record the mass and write your observations

step 3: tearing paper - record your observations

step 4: wet paper - record your observations

step 5: burning pieces of paper - record your observations

step 6: salt and water in test tube - record your observations

step 7: baking soda and vinegar - record your observations

answer the following questions.
what is the difference between a physical change and a chemical change?
what kind of change occurred in each test? what evidence do you have to support your decision? be brief, but be sure to defend your conclusion with data.

Step 1: Burning Candle - Mass- 2.19 The wick of the candle changed colors, from white to black. The shape and height of the candle changed.

Step 2: Cooling Candle - Mass- 2.18, The shape of the has a flat surface.

Step 3: Tearing paper - The paper is somewhat easy to tear, and its edges change shape. It does take a bit to tear it into pieces though.

Step 4: Wet paper - It absorbed the water easily. It became very fragile.

Step 5: Burning pieces of paper - The paper burned fast, it changed color and folded inward and downward.

Step 6: Salt and water in test tube - The water changed color and even bubbled. Small particles of salt dissolve.

Step 7: Baking soda and vinegar - The substance bubbled and changed to a white yet somewhat transparent color.

In chemical changes, composition is the factor that changes, and it's sometimes harder to identify a chemical change as it can't always be seen. Whereas physical changes are more easily identifiable because they include smell, color, anything to do with appearance.

In the candle tests, it was a physical change because its physical appearance changed, such as its height, mass, and color of the wick. The tearing paper test was a physical change too because its physical appearance changed. It’s shape being the main change. I think the burning the paper was both physical and chemical because its physical appearance, the color and shape, changed. But the properties of it changed too, because it went from being paper to being ashes. The salt & water and the baking soda & vinegar were both chemical changes because some properties changed and they formed new substances. Both things caused a gas like substance to form which caused the bubbling formation of both.

Explanation:

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  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-