Physical and Chemical Changes Lab              Name_____________________________

 

Background info –

Matter is constantly changing. The two kinds of changes that occur in nature are physical and chemical changes. In a physical change, no new substances are formed. However, physical properties such as size, shape, color, or phase may change. Dissolving, melting, evaporating, and grinding are examples of physical change.

In a chemical change, one or more “new” substances with new and different properties are formed. The new substances are different from the original substance. Burning and rusting are examples of chemical change.

 

In this investigation, you will observe physical and chemical changes and learn to recognize each type of change when it occurs.

 

PROBLEM:

What are the differences between physical and chemical changes?

 

MATERIALS:

Goggles, foil, toothpicks, candle, paper, matches, glass dish, plastic microplate, salt, water, baking soda, acetic acid, modeling clay

 

PROCEDURE:

  1. Place the small square of foil on your desk top. Put the small candle into a piece of modeling clay so that it is firmly held in the upright position. Light the candle, allow it to burn for 10 seconds, and then gently blow out the flame. Record your observations below.

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Was this a physical or a chemical change? How do you know?

 

 

 

 

  1. Find your small piece of paper. Rip it in half.

Was this a physical or a chemical change? How do you know?

 

 

 

 

  1. Put a piece of your torn paper in the glass dish provided. With your goggles on, carefully light a match, ignite your paper, and allow it to burn, Record your observations below.

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Was this a chemical or a physical change? How do you know?

 

 

 

 

 

4. Find your plastic microplate.  Fill one of the wells halfway with the water in the dropper bottle marked H2O. Add a pinch of salt and stir with a toothpick. Record your observations below.

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Was salt dissolving in water a chemical or physical change?

How do you know?

 

 

 

 

 

  1. In another well on your microplate,  put a pinch of baking soda. Add three drops of acetic acid. Record your observations below.

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     Was this a physical or chemical change? How do you know?

 

 

 

 

 

ADDITIONAL QUESTIONS:

  1. Name some signs that a chemical change might be occurring.

 

 

 

 

 

  1. Can you name a physical change that results in a color change?

How about a physical change that results in gas being released?

 

 

 

 

 

 

  1. You and your lab partner disagree about what kind of change (physical or chemical) happens when salt

dissolves in water. You think it is physical…how can you   try to prove to your partner that salt dissolving in water is a physical change?