By Lin Wozniewski Jamie Cucinotta

 Students must wear:  Closed shoes  Slacks or skirts that come to the ankles  Lab coat or lab apron  Indirect vent or unvented chemical splash proof goggles. No impact glasses or visorgogs are permitted  Long-Sleeved Shirt (if wearing a lab apron)  Long hair (shoulder length or longer) must be tied back.

 Long hair, shoulder length or longer, must be tied back.

Goggles: ANSIZ87 NOT THIS KIND

Their kit. Please check and make sure kids have packed everything they will need. Their kit. Please check and make sure kids have packed everything they will need. NO writing utensils. These will be given to them. NO writing utensils. These will be given to them. They are given one color pen/pencil for their data and another for recording their answers. They are given one color pen/pencil for their data and another for recording their answers.

 test tubes & racks, spot plates, well plates, reaction plates, beakers or similar small containers for mixing  something for scooping & stirring  pH or Hydrion paper  hand lens(es)  Beral pipettes  9-Volt or less Conductivity tester  paper towels  Test tube brush

 Reference Materials  Calculators  Writing instruments of any kind  ANY materials other than on previous slide  Ranking below those who have followed the rules The Penalty?

 Do not have to be fancy or expensive but can be

 1 Substance  1 M HCl  1 M NaOH  2 Different writing instruments  Waste Container  Wash bottle of Distilled Water (ROI)  Instructions about whether refills of the powder are allowed  Instructions on how to use probes or extra reagents

 Any additional equipment or reagents given to the students  So, other equipment will have instructions unless the object is simple.  Ex: a magnifying glass would not have instructions.  Flame loop and Bunsen burner would come with instructions (not happening at States!)

 Thermometer or temperature probes  Balance  Hot plate  Anything else the supervisor decides to distribute. If the supervisor feels instructions are needed in order to use something provided, the instructions will be available

 Phenolphthalein  Hot plate  Thermometer  Benedict’s solution  Silver nitrate  Magnet  Magnifying lens  Iodine  Beaker with boiling water  Universal Indicator  balance

 Observations  The distinction between an observation and an inference  How to prepare students  Scoring the Exam  Resources

 Emphasize to students that the purpose of this lab is NOT to identify the powder. (That is the Science Crime Buster event-not this one)  The purpose is to characterize the powder!  This event hits all of the Middle School National Physical Science Standards.  Therefore it is an excellent event to actually use in the classroom to teach observation and the difference between observation and inference

 Students need to learn to write down observations, not inferences.  Students need to be as specific as possible.  While both flour & cornstarch might at first glance be described as “white powders”, flour is generally more of an ivory white or creamy white, whereas cornstarch is more bright white  Students need to be encouraged to write observations as sentences including what was being observed as well as what was observed.

 Students should do tests on the reagents they are given as well as the powder.  If you do not know for sure if the liquid you are attempting to dissolved the solid in does or does not conduct electricity, you can not say for sure what the solid did  If you do not know what the temperature of the liquid was before you start dissolving, you can not know by how much the temperature changed.

 If the student attempts to dissolve the.1g of the powder in 1 ml of water and the temperature goes down from 22.1  C to 20.9  C, that is an observation  If instead the student writes down that dissolving the powder is an endothermic process, that is an inference.  You would use the first observation to answer the question of whether or not the dissolving is exothermic or endothermic.  But you would get less points for answer 2

 Observations are things that you use your five senses to discern. (No-you are not allowed to taste or touch anything in this lab!)  Inferences are anything that does not use your senses to discern.  So you can see a thermometer and observe a temperature or a temperature change.  But you have to infer that the act of dissolving then takes in or gives off heat based on your observation of the temperature going up or down.

 Students who are careful.  Observant  Good penmanship  Students who clean up after themselves.  Students who work well together, yet can work independently.

 Students should work quickly and get as much data as they can.  They may have minutes for Part I and about 20 minutes for Part 2.

 Have students start by observing powders and reagents and doing sample tests  Students need to make the observations on the reagents first, and then the same observations on the solutions (if any)  Students need to make observations with any “extra” reagents or equipment the event supervisor gives  Students need to get out of the habit of trying to answer the question. They put the observation number as the answer  Coach or assistant scores test and goes over results with students

 Have students get out powders and make up tests for each other  Students score tests themselves  This event is very much like Write-It, Do-It. Students will get unbelievably better if they have to make up questions and score results.

 The questions the event supervisor is likely to ask can be divided into two main categories:  “Standard Questions”  What color is the powder?  Is it a powder or a crystal or a granule  Etc  “Powder specific questions”  You can not ask if dissolving the powder in water is exothermic if the powder is insoluble in water.  Etc.

 Have students pack some paper towels to clean up their mess.  If they use a plastic tub/kit they can just throw everything in there and clean up later.  Points are deducted for leaving a mess. This happened even at Nationals.

 In the data they can say “the temperature went from 12 o C to 15 o C”.  They cannot say the solution was “exothermic”.

 Students get up to 5 points for having the correct data to answer the question.  They can get up to 2 points for no data, but knowing the correct answer.

 Color of powder  Crystal shape  Hardness of crystals  Solubility-make sure they don’t take too much  Density of solid  Take pH of water before adding anything  pH of powder in solution (kids often do this after adding NaOH or HCl)

 Conductivity of the solution  Place a small amount to the side and make an observation after 20min or so if the solid has absorbed water.  Color of the solution before adding any other chemicals.  Be sure to use all the reagents given.  The color of the precipitate should be noted.

 Make sure students do not hold on to test tube when making temperature measurements.  Take temperature of water before adding the powder.  Test the gas given off:  Wet pH paper and hold it over the gas  Be sure to not touch the sides of the test tube  The ammonia gas will turn dark blue

 Know if the substance is ionic or covalent based on data recorded.  Be sure students take the mass of the powder if a balance is available.  Note the odor  Note the luster

Bonus Questions: -Could be to balance an equation -recognize an acid or a base -know the symbols for simple/common elements

 For Event Supervisors   For Lesson Plans for classroom use 