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 the felt is the pen because it is the same sort of ink and size.

<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 tarter <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 - Baking soda <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> Substance D - icing sugar <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> Substance E - corn flour

<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 cream of tater, Substance B is salt <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> Substance C is baking soda, Substance D is icing sugar <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> Substance E is corn flour

<span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;">__Lesson 3 - Fossicking for Fuels Friday 13 April 2011:__

<span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> __Aim:__ to determine properties of different fibres/materials.

<span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> (Record your results on the sheet provided then glue this into your Science book.)

<span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> __Equipment:__ <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 1. 3 different types of material. <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 2. 2 beakers <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 3. 3 test tubes <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 4. Force meter (spring balance) <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 5. Ruler <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 6. Felt pen <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 7. Magnifying glass <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 8. Tongs <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 9. Candle

<span style="color: #000100; font: normal normal normal 26px/normal Chalkboard; margin: 0px;">THE TESTS

<span style="color: #000100; font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> TASK ONE - HOW MANY FIBRES ARE THERE IN THE MATERIAL?

<span style="color: #000100; font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> TASK TWO - WHICH MATERIAL IS THE STRONGEST?

<span style="color: #000100; font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> TASK THREE - WHICH FIBRES SOAK UP THE MOST WATER?

<span style="color: #000100; font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> TASK FOUR - HOW DO THE MATERIALS BURN?

<span style="color: #000100; font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> TASK FIVE - WHICH MATERIALS STRETCH THE MOST?

<span style="color: #000100; font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> (Record results on the sheet provided)

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

<span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> Every person's fingerprint are as different as each person. The use <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> of fingerprints is very important for the police whose only evidence at <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> a robbery might be the fingerprints left by the thief. Police keep a <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> record of fingerprints of criminals in banks of computers.

<span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> Different types of Prints

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

<span style="font: normal normal normal 28px/normal Chalkboard; margin: 0px;">__Your Fingerprints__

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

<span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> Method <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 1. Rub the side of a pencil lead back and forth on a sheet of paper to build <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> up the black area large enough to take 10 prints. <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 2. Press one of your fingertips firmly onto the black. Place the sticky side of a <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> piece of tape over your fingertip. (You may need a friend to help you with this.) <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 3. Tape the print to the correct location on the fingerprint form. <span style="font: normal normal normal 26px/normal Chalkboard; margin: 0px;"> 4. Using the magnifying glass compare your prints to the pictures above and try to label them as either arches, loops or whorls.

My finger prints are a loop and you can tell by looking at my fingers

<span style="font-family: arial,helvetica,sans-serif; font-size: 13px; line-height: 19px;"><span style="font: normal normal normal 26px/normal Chalkboard; margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">__Lesson 5 - Hair Analysis Friday 20 May 2011:__

<span style="font: normal normal normal 28px/normal Arial; margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">Learning Intention: We are learning to

1. think about the process involved in developing a technique for forensic analysis

2. identify the physical structures of hair

3. use our observational skills, critical thinking and microscopy

Background information Unfortunately hair is not the best type of physical evidence for establishing identity. It is not possible to show with any certainty that two hairs came from the same person or animal. However hair can be used to rule out certain suspects or scenarios. It can also be used to corroborate (support) other physical evidence if it is consistent with the rest of the evidence.

Guide to Identification

Cuticle - Outer coating composed of overlapping scales <span style="font: normal normal normal 28px/normal Arial; margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; min-height: 32px;"> <span style="font: normal normal normal 28px/normal Arial; margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">Medulla - Central core, this may be absent <span style="font: normal normal normal 28px/normal Arial; margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; min-height: 32px;"> <span style="font: normal normal normal 28px/normal Arial; margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px;">Cortex - Protein rich structure surrounding the medulla; contains pigment <span style="font: normal normal normal 28px/normal Arial; margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0px; min-height: 32px;">

Fill in the Identification Chart


 * Species || cuticle || cortex || Medulla || Other Charaters ||
 * Human A || Smooth || Thin || Present || Frayed ||
 * Human B || smooth || thin || absent || Narrow ||
 * Horse || spikey || thin || absent || bent ||
 * Dog || Flat || thick || absent || smooth ||
 * Cat || Protruding || thin || broken || frayed ||
 * Rabbit || Smooth || thin || absent || bits of skin ||