Why did Chemistry Become a Science?

Three Primary FactorsBased on needs and wants

Three Primary FactorsBased on needs and wants

• Needs– Shelter from the elements– Food and water– Protection

• Wants– A mate– Improved self-image (status, beauty)– Entertainment

• Needs– Shelter from the elements– Food and water– Protection

• Wants– A mate– Improved self-image (status, beauty)– Entertainment

– Shelter from the elements– Food and water– Protection

– Shelter from the elements– Food and water– Protection

Humans had a many disadvantages

Many animals were:

Bigger

Faster

Stronger

Had sharper teeth

Had tougher skin

Had better vision

Had better sense of smell

Knowing what kind of rocks that were good for making stone tools was critical for survival.

Flint knapping is the art and knowledge of turning stones into tools. (Our wrists are suitable for this)

Near volcanoes, if the melted rock is Near volcanoes, if the melted rock is mostly silica, it can form a natural glass mostly silica, it can form a natural glass called obsidian.called obsidian.

It can be worked into very sharp tools.It can be worked into very sharp tools.

Even today some surgeons use obsidian Even today some surgeons use obsidian knives in eye surgery.knives in eye surgery.

Apache Tears are obsidian, found in Superior

Stone tools technology

• Amazingly, stone tools can be sharper than the surgical knives used today.

• Knives used for cutting meat, cutting hides, cutting fibrous materials.

• Axes used for chopping trees.

• Arrowheads for killing animals at distance.

• All could be used for self-protection

Fire was a huge advance in learning the chemistry of nature and improving chances of survival.

If you want fire, you had to hope for a lightning strike to start it. Then you had to keep it burning.

Learning that fire had important uses.– Warmth– Softens food and makes it

easier to digest– Makes food safer to eat.– Scares away predators.– It causes changes in

materials that are placed in the fire.

Survival with Fire

• Tribes who mastered the creation of fire had much better chances as survival than those who didn’t.

• Even Tom Hanks in Castaway realized the importance of creating a fire.

Dirt became a solution with fire’s help• Once you had fire where ever you wanted, primitive man

would naturally try throwing things into the fire. Sometimes unexpected things happened.

• Sometimes certain dirt that normally would turn to mud when it got wet, would no longer turn to mud, if it had gotten subjected to fire.

• Dirt that could do this was pretty easy to recognize. After rains, and after the ground dried. This special dirt had cracks in it.

• Also, this special dirt could be shaped when it got wet. It was great for making figurines of animals and of beings that possessed special powers.

• But most important was that it could be molded into pots to store and protect food and water.

Firing of Clay

• This special dirt is know as clay. Clay can be molded into a bowl and dried; but if you added water to the bowl, it would become soft and weak and the water would leak out.

• However, if it gets subjected to fire, something very useful happens. It is no longer vulnerable to water and will hold its shape.

SiO2*2H2O

AlO3*2H2O

mullite: Al6Si2O13

Temper

Drying (dehydration)Accelerated evaporation with air and sunAbsorption of water with salt

The bacterium, Acetobacter, converts alcohol to acetic acid (vinegar). Oxygen encourages its growth, highlighting the importance of excluding oxygen during the wine making process.

Mother of Vinegar: A slimy, gummy substance made up of various bacteria — specifically mycoderma aceti — that causes fermentation in wine and turns it into vinegar.

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Even in Middle-Age Europe, it was well-known that spices provide important preservation qualities.The most effective antimicrobial spices include garlic, onion, cinnamon, cloves, thyme and sage. Cloves, which have a high essential oil content, contain eugenol also present in sage and cinnamon.Allicin, present in garlic, also acts as an antimicrobial agent, as does the allyl isothiocyanate present in mustard. Thymol, present in thyme, oregano and sage, is also noted for its antimicrobial properties. Research at Kansas State University, Manhattan, has shown that cloves have a high antimicrobial effect against E. coli in ground meat. Cinnamon, garlic, oregano and sage were also shown to be effective.

Epsom Salts- MgSO4 * 7H2O

Plaster of Paris- CaSO4· 1/2 H2O