Question

hands - on lab
exploring physical and chemical changes
all substances are made of small particles known as atoms and molecules. when a property of a substance changes, its atoms and molecules have changed. the study of chemistry is the study of these changes. some changes happen when one substance interacts with another substance. why might we need to determine how substances interact with one another? we need to be aware of the way substances interact because some changes may be harmful and some may be beneficial.
scientists classify changes in substances as either physical changes or chemical changes. a physical change affects the form of a substance, but its identity remains the same. in a chemical change, however, the chemical identity of a substance changes. atoms and molecules rearrange to form new substances. in this lab, you will determine whether the changes you observe are physical or chemical changes.
research question what are examples of physical and chemical changes that are important in your daily life?
make a claim
preview each experiment you will perform. for each experiment, is the change that occurs physical, or is it chemical? how will you be able to tell what type of change took place?

safety information

• wear indirectly vented chemical splash goggles, a nonlatex apron, and nitrile gloves the setup, hands - on, and takedown segments of the activity.
• immediately clean up any liquid spilled on the floor so it does not become a slip/fall
• never pour chemicals, either used or unused, back into their original container. dispose of chemicals according to your teacher’s instructions.
• if you get a chemical in your eye, use an eyewash station immediately.
• point the test tubes, beakers, or other vessels away from yourself and other people when the vessels contain reactants or other substances.
• never touch, taste, or sniff any chemicals in the lab. if you need to determine odor, waft, hold the chemical in its container 15 cm away from your nose, and use your hand to bring fumes from the container to your nose.
• wash your hands with soap and water immediately after completing this activity.

materials

• indirectly vented chemical splash goggles, a non - latex apron, nitrile gloves
• chalk, calcium
• lead nitrate solution in a bottle, 0.2 m
• mortar and pestle
• silver nitrate solution in a bottle, 0.1 m
• sodium hydroxide solution in a dropper bottle
• sodium iodide solution in a bottle, 0.5 m
• water in dropper bottles
• well plate
• vinegar in a bottle

Explanation:

Physical changes alter form, not identity. Chemical changes form new substances. Examples in daily - life can be identified by these criteria.

Answer:

Examples of physical changes: melting ice. Chemical changes: burning wood.