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Salt…NaCl. sea salt (sharper) vs. brine or rock salt trade – for gold via Timbuktu and Saharan salt fishing trips longer b/c you could preserve fish wartime tactics – destroying saltworks preserving foods 4 oz/body from meat…vegetarians need supplements
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Salt…NaCl • sea salt (sharper) vs. brine or rock salt • trade – for gold via Timbuktu and Saharan salt • fishing trips longer b/c you could preserve fish • wartime tactics – destroying saltworks • preserving foods • 4 oz/body from meat…vegetarians need supplements • taxing …the gabelle…gandhi…british business • soda ash for soap • caustic soda for…extracting al, rayon, cellophane, soap, • detergents, petro products, paper, etc. and • 10. chlorine for disinfectants, pesticides, • polymers and pharmaceuticals.
Chemicals that hurt Napoleon as he attacked then • retreated from Moscow in winter: • TinSb: buttons changed to a weak tin • 2. Salt NaCl: lack of dietary salt prevents wounds from • healing • 3. Ascorbic acid – Vitamin C - soldiers died of scurvy.
III. A polyatomic ion is a group of atoms that: 1. covalently bond to each other, but are 2. ionic bonded to metals. Ex. hydroxide OH- H shares an e- with O: covalent bond To form sodium hydroxide NaOH, the Na transfers an e- to OH: Na+ + OH- = KOH ionic solid O H
NaOH sodium hydroxide (aka lye or caustic soda) is used in: cleaning paper and soap making food prep
Ex. nitrate NO3-1 covalent bonds O N O O In potassium nitrate KNO3, K transfers an e- to the nitrate. K+ + NO3- = KNO3 ionic solid
KNO3 is used in: gunpowder tree stump removers toothpaste for sensitive teeth food preservative
IV. Metallic bonds - e- can leave the atoms mobile (free) - leave behind a positive ion - negative sea + positive ions = metallic bond - mobile e-s make good conductors
positive ions
Summary: (M = metal, N = nonmetal) bond atom type Ex substance ionic M-N NaCl ionic solid covalent N-N H2O molecule polyat. ions M-(N-N) CaCO3 ionic/molecule metallic M Ag mobile