Chapter 1 The Science of Chemistry. Chemistry is:. Chemistry is the study of matter and all the changes it undergoes or fails to do. Name 3 chemicals. Should we ban chemicals?. A. States/Phases of Matter. Solids (s) Held tightly Vibrate slightly Fixed volume & shape Draw.
Chapter 1 The Science of Chemistry
Chemistry is the study of matter and all the changes it undergoes or fails to do.
Should we ban chemicals?
Definite volume & No shape
No definite volume or shape
Ex. Phase change slg ice melting
Ex. Dissolve sugar/salt in water
2. Chemical New substance made
Ex. Burning, rusting
Ex water hydrogen + oxygen
Reactant(s)- Left side of equation what exist before rxn
Product(s)-Right side of equation what exist after rxn
2.Make precipitate (ppt)- when 2 chemicals don’t mix & one settles at bottom
3. Release/absorb energy (heat)
4. Might be a color change ex. rust
1a. .765g x 1kg = .000765kg
1b. 1.34g x 1,000mg = 1,340 mg
1c. 34.2mg x 1g = .034g
1d. 23,745kg x 1,000g =23,745,000g x 1,000mg =
2a 17.3m x 100cm = 1,730cm
2b. 2.56m x 1km =.00256km
2c 567dm x 1m= 56.7m
2d 5.13m x 1,000mm = 5,130mm
Pure Substance: a sample of matter, an element or a compound that has definite chemical & physical properties, always the same, pure.
element: only one type of atom.
Define:simplest form of matter that cannot be broken down
Some elements may be monoatomic consist of one atom such as He, Al, or Ca.
Some elements may be molecules:2 or more atoms combined in a definite ratio
Ex. H, O,N,F, Cl,Br,I are diatomics!!! Mark your periodic tables!!!! HON all Group 17
Some elements have more than one form, Allotropes(define)same element, same phase of matter but different physical & chemical properties
Example(book) O2(g O3(g) (also Carbon-coal, diamond, graphite, all solids but different forms)
Compound (cmpd); 2 or more elements chemically combined
Molecular formula: condensed formula C6H12O6
Subscript; # placed lower right of element/cmpd; tells us how many atoms
Structural formula: (draw out) shows arrangement
Mixture: 2 or more substances (elements/cmpds) physically combined
Ex. Alloy= solid mixture: 10, 12, 14, 18K gold
Stainless steel: homogeneous
Brass= Cu + Zn
Homogeneous; same throughout; uniform. Solns, air
Heterogeneous: not uniform; different amounts or parts ex. Italian salad dressing, sand in water