CSI



Learning Intentions:

 1. To become familiar with //chromatography// and be able to apply it to 'real life'  situations.

 2. To perform 'fair tests' in Science identifying substances and fibres.

 3. Identify and group fingerprintsinto 3 main categories: Arch, Loop  and Whorl.

 4. Set up and carry out Scientific Experiments following the correct process  of; Aim, Equipment, Hypothesis, Method, Results and Conclusion.

 5. Work collaboratively with peers to solve problems using the skills learnt.

Lesson One - Paper Chromatography

Chromatography is a technique used for seperating mixtures. In all of the variations of Chromatography, a substance is placed onto or into a medium and then a solvent passes through the test substance, some of the test substance may be attracted to the solven and follow it up in the medium. Different types of molecules are transported different distances, causing them to seperate. In these activities, filter paper is the medium, solvent is the solvent and black ink is the test substance. Chromatography is used in crime labs to seperate the components of 'clue' substances such as blood, ink or other mixtures found at the scene of a crime. Chromatograms of these clue substances are then compared with those of the suspected sources.

__Chromatography Monday 9th May 2011__

 __L.I__ I am learning the process of the chromatography and use this  to assist with solving the crime.

 __Aim:__ To use chromatography to distinguish which pen was used in the ransom note.

 __Hypothesis:__ I think that ......................because.............

<span style="font: normal normal normal 18px/normal Chalkboard; margin: 0px;">Black marker x5 <span style="font: normal normal normal 18px/normal Chalkboard; margin: 0px;"> Casade marker x14 <span style="font: normal normal normal 18px/normal Chalkboard; margin: 0px;"> Sharpie x3 <span style="font: normal normal normal 18px/normal Chalkboard; margin: 0px;"> Vivid x4

<span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;">__Equipment -__ Beaker, felt pens, ransom note, filter paper, water, hand lens, masking tape and straws.

<span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> Method:

<span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 1. Gather samples of pens. <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 2. Draw a line across a strip of filter paper, 1-4cm from the bottom. <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 3. Attach to straw with masking tape. <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 4. Put filter paper in beaker, making sure the ink is at least 1-2cm above <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> the water. <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 5. Observe. <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 6. Remove filter when water has travelled about 3/4 of the way up the strip. <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 7. Compare results with the ransom note results.

<span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> Results - <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 1. Black Ballpoint Pen <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 2. Vivid <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 3. Cascade marker <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 4. Sharpie <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 5. Black marker

<span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> Reflection - (write here what you have learnt during this lesson).

__Lesson Three - Kitchen Chaos Wednesday 11 May 2011:__

<span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> The kitchen cupboard has got very damp and the labels have fallen off some <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> of the containers. From the label scraps it is found that there is:

<span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> Icing sugar <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> baking soda <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> salt <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> cream of tartar <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> cornflour

<span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> TASK - Make order out of chaos

<span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> Use a series of simple tests and good observations to find out what substance is in <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> each container.

<span style="color: #009f00; font: normal normal normal 26px/normal Chalkboard; margin: 0px;">Caution: You are not allowed to taste them! Please use small quantities.

<span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> Aim: to find out what the substance is by carrying out a series of simple tests.

<span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> Hypothesis: <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> I think that the substance in the different containers is;

<span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> Substance A - Cream of Tatar <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> Substance B - Salt <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> Substance C - Corn Flower <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> Substance D - Baking Soda <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> Substance E - Icing Sugar

<span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> Equipment - Five containers with the different substances labelled A, B, C, D, E. <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> - Eyedroppers <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> - Vinegar <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> - Magnifying Glass <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> - Litmus Paper (red and blue) <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> - Iodine

<span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> CLUES TO HELP YOU.......................

<span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 1. Cream of tartar is an acid, and turns blue litmus paper red. <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 2. Cornflour and sugar are neutral and don't affect litmus paper. <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 3. Salt and bicarbonate of soda are alkaline, that is they turn red litmus paper blue <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 4. Bicarbonate of soda fizzes when mixed with vinegar. <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 5. Iodine changes from yellow-brown to blue-black with cornflour. <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> There are many different ways of telling the differences between substances. <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> You could:


 * Smell them carefully.
 * Compare the way they dissolve in water.
 * Examine with a magnifying glass.
 * Test the acidity with litmus paper.
 * Test the reaction with vinegar and iodine.

<span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> Results: <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> Substance A is Corn Flower Substance B is Salt <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> Substance C is Backing Soda Substance D is Icing Sugar <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> Substance E is Cream of Tatar

<span style="font: normal normal normal 26px/normal Chalkboard; margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">Lesson Four - Finger Prints __Wednesday 18 May 2011__:

Every person's fingerprint are as different as each person. The use of fingerprints is very important for the police whose only evidence at a robbery might be the fingerprints left by the thief. Police keep a record of fingerprints of criminals in banks of computers.

Different types of Prints

<span style="font: normal normal normal 26px/normal Chalkboard; line-height: 0px; margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; overflow-x: hidden; overflow-y: hidden;"> Loop Whorl Arch

<span style="font: normal normal normal 28px/normal Chalkboard; margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">__Your Fingerprints__

<span style="font: normal normal normal 26px/normal Chalkboard; margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">Equipment - Pencil, Paper, Sticky tape, Magnifying glass.

Method 1. Rub the side of a pencil lead back and forth on a sheet of paper to build up the black area large enough to take 10 prints. 2. Press one of your fingertips firmly onto the black. Place the sticky side of a piece of tape over your fingertip. (You may need a friend to help you with this.) 3. Tape the print to the correct location on the fingerprint form. 4. Using the magnifying glass compare your prints to the pictures above and try to label them as either arches, loops or whorls.