Microanalysis in Science and Engineering Identification of Solids Physical Science

Contact Information Susan Upton and Deborah Sells Livingston Academy

Performance Indicators Physical Science Standards – State of TN – Standard 2.0 Structures and Properties of Matter The student will be able to identify samples of matter as solid, liquid, gas, or plasma.

Textbook Reference Foundations of Physical Science Tom Hsu (CPO 2002) – Chapter 16 What is Matter ?

Internet References Images used in this slide show were obtained from the following websites: mayo snow CO2 glass fracture surface sea salt sugar crystal (red) diamond acid crystals gypsum plastic Various clip art images Mouse detective clipart Tupperware Tennessee The salt and sugar crystal micrographs were taken by us during the workshop at TTU.

Materials Needed Materials Needed for this activity: – Samples of sugar, salt, glass, plastic – Hand lens – Textbook or web access

What Makes A Solid Be A Solid ? Are These Solids ???

Investigation 1. Do you think each is a solid? 2. Look at each of the samples in front of you. 3. Why do you think each is or is not a solid? Record your answers on your lab handout.

Find the information Look up the definition of a solid, either in your textbook or on the internet. – One possible website is ~jimaskew/pphase.htm Write the definition on your lab handout.

Take a closer look Now look at each sample using the hand lens. Do you still agree with how you classified the samples originally? Record your answers on your lab handout.

Take a really close look Now you will look at pictures of each of the substances taken at high magnification using an electron microscope. This allows you to see more detail than possible with the human eye or the hand lenses. After looking at the pictures, decide if your original classification of each substance fits the definition of a solid. Record your answers on your lab handout.

Salt Sugar GlassPlastic

Explanation Explain why each sample is or is not a solid, based on the definition of a true solid. If a sample is not a true solid, what is it? – Use your textbook or the website to find out. Record your answers on your lab handout.

Answers The sugar and salt are true solids because they have a crystalline structure. The glass and plastic are not true solids because they do not have a crystalline structure. – Amorphous refers to substances that appear to be solid, but really aren’t, like the glass and plastic.

Now Try These Now that you know what a true solid is, see if you can identify the following pictures.

Answers to “Now Try These” If you said all of the samples were true solids, you missed one. The picture in the lower right hand corner is not a solid because is does not have a crystalline structure. – The images were solid carbon dioxide (dry ice), sea salt, sugar, and mayonnaise.

Evaluation Use the rubric to see how well you have mastered this material. See if your self-assessment matches how well your teacher thinks you did.

Rubric ExcellentGood Satisfactory Poor Following Directions Student completes tasks without aide of teacher. Student needs only limited guidance from teacher. Student is unable to follow directions without repeated help from teacher. Student needs constant teacher aide, unable to follow directions on own. Correct Identification Student identifies 100% of samples correctly Student identifies % of samples correctly. Student identifies 50-75% of samples correctly. Student identifies less than 50% of samples correctly. Lab Procedures Student follows correct lab safety procedures without being reminded. Student follows correct lab procedures after being reminded. Student must be repeatedly reminded of correct lab procedures. Student does not follow correct lab procedures, even after being repeatedly reminded. Ability to Access Information Student is able to find information without assistance. Student needs only limited help in finding information. Student needs extensive help in finding information. Teacher must find information for student.

End Notes Special thanks to: – Dr. Margaret Phelps – Dr. Larry Knox – Dr. Chris Wilson – Dr. Joe Biernacki – Wayne Hawkins – The ever helpful graduate students