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QUIZ: Early Uses of Chemistry
Checking your understanding of Stone Tool Technology, Clay Chemistry, and Preservation Chemistry
Last updated 8-20-08

Copy the questions below (highlight the text, then press the CTRL key plus "c", or use the Edit menu at top and choose "Copy")
     In your email program start composing an email and paste the questions to your email (use CTRL-V to paste or use Edit menu and choose "Paste"). I don't need the images. You can then answer them in your email and send it to me at chm130@chemistryland.com.

Question 1: Even though extinct now, the saber tooth tiger probably gave early man much to fear and was a fierce competitor for food. In what ways do you think the saber tooth tiger was superior to the humans of that time (last ice age)

Question 2: The image on the right is a boulder of obsidian. Obsidian was the mineral of choice by prehistoric hunters for making knives and arrowheads. It is still used today by some surgeons where the sharpest blade is needed. One company which sells surgical tools also carries the obsidian scalpel. Visit this Web page and find out the price for an obsidian scalpel with a 12mm (1/2 inch) blade.


http://www.finescience.com/...obsidian-scalpels.htm

Question 3: Another mineral used for making stone tools was flint. Flint is also glass-like. The arrowheads to the right are made of flint. They are sharper and harder than steel. Flint is so hard that when it strikes a piece of steel, the flint scratches the steel and particles of steel fly off white hot as they burn in the air. For this reason flint was used in the old "flintlock" guns to ignite the gunpowder. Now it is used in cigarette lighters and in as a foolproof way to start a fire in wet environments. Do a search of the Web for "flint firestarters" What did you learn about them?


Question 4: Since "flint" is a common mineral used for stone weapons and "knapping" is a German word meaning to "break a piece off", flintknapping is the art of breaking pieces off of flint (or other suitable minerals) for the purpose of making stone tools or weapons. Search the Web for flintknapping and find a person who is a flintknapper and which state are they from.
Question 5: Stone arrowheads apparently were sharp and hard. However, their real effectiveness came from being attached to an arrow shaft, which could hit something at a good distance. Even today, many hunters prefer the bow and arrow because of its stealth and lethal power. Search the Web and try to find the world distance record for shooting an arrow.

Question 6: Scenario: You are walking along a dry river bed and come across a dog that has gotten tangled up in some rope. The rope is too knotted and stiff for you to untie it. You need a knife to cut the rope but don't have one. What could you do?


Question 7: If this woman was to leave the grain outside for a few days, what might happen to it? (other than someone stealing it)

Question 8: Earthenware is clay fired at a low kiln temperature around 1400-2000°F . Earthenware is not very strong and is porous.
Stoneware - harder than earthenware, stoneware is fired at about 2200-2400°F. Stoneware is strong and can hold water, though is not completely water proof unless glazed.
Porcelain - a special type of clay either white or grey, to which kaolin (a white firing stiff clay) and white China stone (finely decayed granite) is added. When fired at temperatures of 2300°F and over (up to 2550°F was achieved by the Chinese), the body vitrifies, i.e. it becomes glass-like and completely impermeable.
Let's say you built a kiln that used aluminum, iron, copper, and chromium parts. Which of those metals would melt if the oven was taken up to 2400°F (1315°C)
(hint: search for "melting point metals").

Question 9: On the right are formulas for four different clays. What three elements are found in each of these clays? Also, notice that "talc" is a clay. You know it as the main ingredient in talcum powder; however, being a clay, talc can be heated to make porcelain-like dinnerware. They call it steatite porcelain. Sometimes these formulas are written to show the water, for example, kaolinite is also written Al2O3·2SiO2·2H2O. The element count is the same, but you can better see the water (H2O) that will be driven off upon heating.

Question 10: Cooking is one of the most common ways to extend the life of food. However, cooking must raise the food to certain temperatures to kill the bacteria in the food. Check the Web for the minimum safe cooking temperature for, let's say, ground beef.
Question 11: Cooking dries food to some extent, but smoking, sun drying, or air drying was used to extend the life of food even more. Nowadays they make dehydrators to assist with this. Find a site that sells food dehydrators. Give the address for the site. Now as a separate task, see if you can attach an image of a food dehydrator. To get an image off of a Web site, move cursor over it and click right mouse button. (For Mac users just hold mouse over image for awhile) A menu should appear. Choose "Save Picture As..." if using Internet Explorer, or "Save image as..." if using Netscape. When you email your answers, see if you can attach the picture to the email.

Question 12: Garlic is known for its antibiotic capabilities. The first structure, alliin, is contained in garlic but has no antibiotic properties. When crushed, an enzyme (alinase) in the garlic comes in contact with "alliin" and removes the right half . Note: C=carbon, H=hydrogen, S=sulfur, O=oxygen.

The enzyme takes two halves from two Alliin molecules and...

...and as the two halves are joined, water is released.

The result is the compound, "Allicin," which is very antibiotic. This compound gives garlic its known antibiotic properties.
However, when cooked, the Allicin breaks down into diallyl-disulfide. Unfortunately, this is not antibiotic. So garlic in cooked foods is not as healthy. What's the difference in the molecules of Allicin above and diallyl-disulfide shown to the right?
Congratulations on getting through your first quiz. Send your answers to me at chm130@chemistryland.com
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