Chemistry Practice -1st Semester Safety and Measurement Lab Safety Flammable materials, like alcohol, should never be dispensed or used near an open door. an open flame. another student. a sink. If a laboratory fire erupts, immediately notify your instructor. run for the fire extinguisher. throw water on the fire. open the windows. Approved eye protection devices (such as goggles) are worn in the laboratory to avoid eye strain. to improve your vision. only if you don’t have corrective glasses. any time chemicals, heat or glassware are used. If you wear contact lenses in the school laboratory, take them out before starting the lab. you do not have to wear protective goggles. advise your science instructor that you wear contact lenses. keep the information to yourself. If you do not understand a direction or part of a lab procedure, you should figure it out as you do the lab. try several methods something works. ask the instructor before proceeding. skip it and go on to the next part. After completing an experiment, all chemical wastes should be left at your lab station for the next class. disposed of according to your instructor’s directions. dumped in the sink. taken home. If a lab experiment is not completed, you should discuss the issue with your instructor. sneak in after school and work alone. come in during and finish while eating lunch. make up some results. You are heating a substance in a test tube. Always point the open end of the tube toward yourself. toward your lab partner. toward another classmate. trial
Why does liquid candle wax flow but solid candle wax does not? Because the molecules of liquid candle wax are softer than the molecules of solid candle wax Because the molecules of liquid candle wax weigh less than the molecules of solid candle wax Because the molecules of liquid candle wax are moving but the molecules of solid candle wax are not Because the molecules of liquid candle wax can easily move past one another but the molecules of solid candle wax cannot You drink all of the water from a plastic bottle. You put the cap on the bottle and tighten it. Then you put the bottle in the refrigerator. An hour later, you notice that the bottle is dented. Why is the bottle dented after being cooled in the refrigerator? All the molecules of air went out of the bottle. Heat molecules inside the bottle were destroyed. The molecules of air inside the bottle down. The molecules of air inside the bottle got closer together. A glass thermometer has a colored liquid inside it. The level of colored liquid rises when the thermometer is placed in hot water. Why does the level of liquid rise? molecules are pushed into the thermometer. Heat molecules push the molecules of the liquid upward. Heat causes the molecules of the liquid to get farther apart. The molecules of the liquid break down into atoms and take up more space. How do the molecules of hot air differ from the molecules of cold air? The molecules of hot air are farther apart than the molecules of cold air. The molecules of hot air have less mass than the molecules of cold air. The molecules of hot air have more heat molecules mixed with them. The molecules of hot air are smaller than the molecules of cold air. How do the molecules of cold water differ from the molecules of hot water? The molecules of cold water are larger than the molecules of hot water. The molecules of cold water have fewer heat molecules mixed with them. The molecules of cold water have more mass than the molecules of hot water. The molecules of cold water are closer together than the molecules of hot water. Describe how matter is classified by state of matter and by composition Which of the following materials cannot be broken down into a simpler form? Compound Solution Mixture Element What the following be classified as: N Element Compound Mixture Chemical reaction What would the following be classified as: Si