Physically Changing Glass

Transcription

1 Physically Changing Glass Part A: Notes I. States of Matter a. There are four states of matter on Earth: i. ii. iii. iv. (Circle the states above that we can easily observe in our science lab.) b. Matter changes from one state to another by changing II. III. Kinetic Molecular Theory of Matter a. Explains the effect of and pressure on matter b. All matter is composed of small i. These particles are in motion c. Kinetic Molecular Theory of Solids i. Solids have a shape and volume ii. Particles have side-to-side movement, but they do vibrate iii. When solids melt, heat is iv. Glass, when heated, changes into an state 1. solids are not true solids, rather they are in between the solid and liquid phases Thermal Conductivity a. A property i. Refers to the ability for a substance to transfer b. Glass is a thermal conductor i. This means that heat transfer easily through it Labs and Projects 1

2 Part B: Glass Safety SAFETY CONTRACT FOR: HEATING SUBSANCES USING A BUNSEN BURNER 1. I WILL be extremely cautious when using a gas burner. I WILL make sure that my hair, clothing and hands are a safe distance from the flame at all times. I WILL NOT put any substance into the flame unless specifically instructed to do so. I WILL NOT reach over an exposed flame. I WILL light gas burners only as instructed by the teacher. 2. I WILL NEVER leave a lit burner unattended, or anything that is being heated unattended. I WILL NEVER leave my work station. I WILL always turn the burner off when not in use. 3. I WILL remember that heated metals and glass remain very hot for a long time. I WILL set them aside to cool and WILL pick them up with caution. I WILL use heat-protected gloves when instructed to do so. I WILL wait at least one minute before touching heated lab equipment. 4. I WILL NEVER look into a container that is being heated. 5. I WILL wear safety goggles and an apron to protect myself when working with a Bunsen burner. 6. I WILL NEVER touch myself or others with heated materials. When using glass materials, I WILL remember the following: glass tube endings are sharp and I should never walk or run with glass. Hot glass burns skin and must be cooled before touching. I will never touch another student with hot glass, or put hot glass under cold water or on cold desktops. I will not put glass in the trash can or in the sink. I WILL NEVER take glass outside the science classroom. 7. I UNDERSTAND that if I do not follow the above rules and regulations, consequences as deemed by the teacher will follow. Printed Name: Signature: Date: Labs and Projects 2

3 Part C: Glass Skills MAKING A NINETY-DEGREE BEND: Use a 30 cm piece of glass. Heat and roll the middle. When soft, take out of the fire and bend to the desired angle. Check it with a corner angle to measure for accuracy. MAKING A RIGHT TRIANGLE: Cut a piece of glass to fit the open side of your ninetydegree bend. Weld the newly cut piece by heating two ends at the same time and then touching them together. Do the same with the last open corner. You should end up with welds on two corners. MAKING A HEART: Using two 30 cm pieces of glass, heat and roll the top third of the glass. When soft, take out of the fire and bend to a 45-degree angle. Then, weld the ends of the pieces. MAKING A BUBBLE: Fire polish one end of a 30 cm piece of glass. Let the glass cool for 5 minutes. Then place the opposite end of the glass into the flame. Rotate it until it is completely closed. Then blow into the glass through the fire polished end and slowly remove the glass from the flame while blowing. Labs and Projects 3

4 Pop Quiz Fill in the blanks below. 5 THINGS TO DO YOURSELF BEFORE LIGHTING BURNER 1. Tie back long. 2. up sleeves or remove clothing. 3. Put on. 4. Put on a heat resistant. 5. Put away materials. 3 THINGS TO CHECK BEFORE LIGHTING BURNER 1. Check that the gas is in the OFF position ( to the gas outlet). 2. Check that the valve on the bottom of the Bunsen burner is off. 3. Check that the (air vent) is closed. 4. Check the hose for. LIGHTING THE BUNSEN BURNER 1. Connect hose securely to gas and Bunsen burner. 2. Turn on the gas outlet. 3. Turn the on the Bunsen burner about turns. 4. Turn the gas on the Bunsen Burner about turns. 5. Light burner immediately using the striker. 6. After burner is lit adjust the gas valve so that the flame is about 2-3 inches high. Labs and Projects 4

5 Part D: Conclusions In the space below, provide specific evidence that proves our work has resulted in physical changes. Support your reasoning by explaining how this work CANNOT represent chemical changes. RUBRIC Expectation Level All Information Included (3) Partner Work and Contributions () Focus on the Task and Safety () Due Date () Exceeding All information is included and very thorough, including teacher initials for glass skills 3 Creates a positive and constructive environment in which everyone in the partnership can thrive; contributed significantly to the project Always on task; no redirection needed; was always safe Glass sculptures and packet turned in on time Meeting Approaching Below All information is included, but not thorough (ie minor parts missing from any of the parts) Missing some parts of the information pts Missing many parts of the information, but still participated in the project 20-2 Listens to the opinions of others and makes constructive contributions to the team effort. Cooperates as a team member but makes few original contributions to the effort or makes contributions to the team, but doesn t cooperate as a team member Requires prompting in order to function as an effective member of the team. Overall focused on task; may have been slightly distracted; overall safe Need some redirecting to remain focused; showed a few safety concerns Lack of focus or effort to remain focused; redirection needed several times; showed many safety concerns Packet turned in on time Glass sculptures turned in on time Neither component (sculpture and packet) turned in on time Labs and Projects 5