Chem Quiz #1 Flashcards
Define element
a type of matter composed of atoms w/ the same atomic # (substance can only correspond to 1 element on periodic table)
Allotrope
Diff. STRUCTURAL forms of the same element in the same phase
- diff. forms can have diff. reactivity
Examples of allotropes
Carbon: Diamond, graphite, & fullerenes
Oxygen: dioxygen (O2) & Ozone (O3)
Sulfur: orthorhombic, monoclinic, amorphous (30 others)
Phosphorus: red, white, & black
Photocatalytic water splitting
Uses sunlight to split H20, butt electrolysis energy doesn’t compensate for energy spent
Compound
substance that contains 2 or more elements
Binary compound
Contains 2 elements
Binary compound examples
H20, H202, CO, & CO2
Ternary compound
Contains 3 elements
Ternary compound examples
C2H5OH (ethanol)
Quaternary compound
Contains 4 elements
Polymorphs
Diff. structural forms of the same COMPOUND in the same phase
Polymorph examples
TiO2 (Anatase & Kutile)
Organic compound made w/
Carbon, Hydrogen, Oxygen, & sometimes Nitrogen
Prussian Blue
absorbs thallium & is treatment for radioactive exposure
Fe4[Fe(CN)6]3
Mixtures
Combination of 2 or more elements/compounds
Example of a mixture
Salt Water (NaCl + H20), Brass (Cu + Zn)
Heterogeneous
Can be physically separated (not uniform)
Heterogenous ex.
solid mixture of blue Cu(NO3)2 x 6H20 & yellow Cds
or
Cereal
Homogeneous
mixed @ molecular level butt NOT chemically bonded
- properties don’t vary through the sample
- can be separated butt not easily
Homogeneous ex.
NaCl + Water or air
Pure Substance
only an element or compound
Material
sample of unknown composition & may be a pure substance/mixture
Greek root of atom
atom (not) tomos (cut)
1st evidence for existence of atoms
analyzing weights of products & reactants