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Chapter 12 Part 2. DO NOW. How have discoveries in chemistry impacted people’s health and lives?. Lesson 4 – Chemistry and Health ( pg 386). Alexander Fleming discovered penicillin which led the way to antibiotics. They are used to kill bacteria.
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DO NOW • How have discoveries in chemistry impacted people’s health and lives?
Lesson 4 – Chemistry and Health (pg 386) • Alexander Fleming discovered penicillin which led the way to antibiotics. They are used to kill bacteria. • Vitamins are chemicals that are naturally found in certain foods and prevent many diseases. • Fertilizers are chemicals used by farmers to help food to grow
Silk is a very nice expensive material Made from silk worm cocoons
A french scientist made artificial silk But it easily burst into flames
Chemistry and New Materials (pg. 388) • Many materials used daily come from nature, but others were created by scientists. • Scientists worked to create a synthetic replacement for silk and eventually invented polymers. Polymers are large molecules made of identical small units connected together. • Some useful synthetic materials are plastic and cement.
The PROBLEM with Natural Rubber: • IT gets GOOEY and MELTY in hot weather! • IT gets BRITTLE and CRACKS in cold weather.
In the 1800’s: • Scientists experimented with natural rubber and added HEAT and SULFUR. • This made it more durable!
In the 1900’s • Chemists developed artificial rubber.
Petroleum is made up of: • Gasoline, • Kerosene • Diesel oil • Lubricating oil • Chemists found a way to separate gasoline molecules from the mixture petroleum!
What does SYNTHETIC mean?? • Hint : • synthesize
Natural Materials? Or synthetic? (What does synthetic mean?) • Cotton • Wool • Plastic • Nylon • Concrete • Silk
CHEMISTRY and TRANSPORTATION • Rubber for tires! • Petroleum for gasoline! • Mix of metal elements (combined in a factory or plant) and plastic (made in a lab) for car
Chemistry and New Materials • Cotton in jeans • natural • Wool in a sweater • natural • Nylon in stockings • Made in a lab • Plastic • Made in a lab • Concrete • Made in a lab!
Chemicals—Helpful vs Harmful • Chemicals are helpful when used properly!
Chemicals for Cleaning Common chemical bleaches include household chlorine bleach, a solution of approximately 3–6% sodium hypochlorite (NaClO), and oxygen bleach, which contains hydrogen peroxide or a peroxide-releasing compound such as sodium perborate • Bleach • Ammonia • Oven Cleaner
Care with Chemicals! • READ THE DIRECTIONS! • Gloves • Goggles • Open window • Do not mix without proper knowledge! • Or else: chemical reactions, lung damage, fumes, burns, explosions, death!
How Does temperature affect how long a reaction takes? – alka seltzer lab
MODELS • Model = • A useful way to understand a subject that you maybe cannot see or explore in real life • (ex: using magnets to explain what happens in a chemical reaction) • (ex: a globe to understand what the earth looks like)
Types of Chemical reactions • 1. combination • Elements or compounds come together to form new compounds • A + B AB • 2. decomposition • Compounds split apart to form smaller compounds or elements • AB A + B • 3. replacement • Compounds split apart and parts switch places • AB + CD AD + BC