1. Candle: Burns lighter, leaves ash, smells.
2. Cooled: Hard, brittle wick, less wax.
3. Torn paper: Rough edges, exposed fibers, rip noise.
4. Wet paper: Weak, heavy, dark, tears easily.
5. Burning paper: Quick, bright flame, ash, smoke.
6. Salt & water: Clear, salty, no bubbles.
7. Baking soda & vinegar: Fizzy, cloudy, CO2, vinegar scent.
Step 1: Burning Candle
* Mass:The mass of the candle before burning will be higher than its mass after burning. This is because combustion consumes part of the candle's mass, releasing energy and leaving behind residues like ash and water vapor.
* Observations:
* The flame dances and flickers, emitting light and heat.
* The wick turns black and melts as it draws molten wax upward.
* Smoke rises from the flame, carrying unburnt fuel particles.
* A liquid pool of wax forms around the base of the wick.
* The surrounding air becomes warmer.
Step 2: Cooling Candle
* Mass: The mass of the cooled candle will be slightly less than the mass before burning due to the loss of material through combustion and evaporation.
* Observations:
* The flame extinguishes, leaving a wisp of smoke.
* The wick solidifies and becomes brittle.
* The molten wax cools and hardens, forming a new layer on top.
* The pool of liquid wax shrinks as it solidifies.
* The surrounding air cools down.
Step 3: Tearing Paper
* Observations:
* The paper tears unevenly, creating rough edges.
* The fibers of the paper separate and become visible.
* A ripping sound is produced.
* Depending on the type of paper, it may tear with a clean line or splinter into smaller pieces.
Step 4: Wet Paper
* Observations:
* The paper loses its rigidity and becomes limp.
* The water spreads through the paper fibers, darkening it.
* The paper becomes heavier and less tearable.
* If the paper is saturated, it may start to disintegrate.
Step 5: Burning Pieces of Paper
*Observations:
* The paper ignites quickly and burns rapidly with a bright, flickering flame.
* The flame produces ash and smoke.
* The burning process is faster than with a candle due to the paper's high surface area.
* The paper shrinks and crumples as it burns.
Step 6: Salt and Water in Test Tube
* Observations:
* The salt crystals dissolve in the water, forming a clear solution.
* Depending on the amount of salt and water used, some crystals may remain undissolved initially but will eventually dissolve with agitation.
* No gas bubbles are produced.
Step 7: Baking Soda and Vinegar in Test Tube
* Observations:
* A vigorous bubbling reaction occurs as the baking soda (sodium bicarbonate) reacts with the vinegar (acetic acid).
* Carbon dioxide gas is produced, causing the mixture to foam and fizz.
* The solution becomes cloudy due to the formation of sodium acetate.
* A slight vinegar smell may be present.
Please note that these are general observations, and the specific details may vary depending on the materials used and the conditions of the experiment.