why did chemistry become a science n.
Skip this Video
Loading SlideShow in 5 Seconds..
Why did Chemistry Become a Science? PowerPoint Presentation
Download Presentation
Why did Chemistry Become a Science?

Why did Chemistry Become a Science?

110 Vues Download Presentation
Télécharger la présentation

Why did Chemistry Become a Science?

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Why did Chemistry Become a Science?

  2. 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

  3. NEEDS

  4. Extreme competition for food Getting it Keeping it Not becoming food yourself

  5. 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


  7. Knowledge of Rocks 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)

  8. Obsidian Near volcanoes, if the melted rock is mostly silica, it can form a natural glass called obsidian. It can be worked into very sharp tools. Even today some surgeons use obsidian knives in eye surgery.

  9. Apache Tears are obsidian, found in Superior Obsidian

  10. 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

  11. Agate (mostly quartz)

  12. Agate mortar & pestles

  13. Stone tools gave humans Stone tools gave humans the edge needed to survive the edge needed to survive

  14. HUNTING AND GATHERING OF FOOD FOOD & WATER STORAGE Store food and water for times of shortage Protect it against the weather and pests

  15. How do you store food and water?

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

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

  18. 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.

  19. 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.

  20. Dirt became a solution with fire’s help The problem of food & water storage • 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.

  21. CLAY

  22. 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.

  23. Quartz Silicon and oxygen atoms stacked tightly

  24. SiO2*2H2O AlO3*2H2O mullite: Al6Si2O13 Temper

  25. Store food in a way to protect it against the weather and pests

  26. Later glass blowing helped civilizations in the storage of food & drink

  27. PRESERVATION OF FOOD Create environment that inhibits spoilage

  28. Cooking

  29. Drying Beef Jerky Drying (dehydration) Accelerated evaporation with air and sun Absorption of water with salt

  30. Bacteria Mold Controlled fermentation and separation Yeast alcohol