Appendix - Section 1.5 Flashcards
Rules of Adding and Subtracting Exponents
Powers must be the same.
To multiply exponents
Add exponents
To divide exponents
Subtract exponents
Raising exponent to a power
Number is raised to the power and exponent is multiplied by power.
Elements are composed of _____.
Atoms
Each element is composed of ______.
Unique Atoms
Molecules are ______ atoms joined together in a specific arrangement.
Two or more
Physical States of Matter
Solid (s), Liquid (L), Gas (G)
States of matter can interconvert between states by varying ____ and/or ____.
temperature, pressure
Gas
Has no fixed volume or shape and can be compressed or expanded.
Liquid
Has distinct volume but no shape.
Solid
has a definite shape and volume.
Neither solids or liquids are compressable to any appreciable extent.
.
A “Pure Substance”
- Has distinct properties
- Composition does not vary from sample to sample.
- All pure substances are elements or compounds.
Elements
- Cannot be decomposed into simpler substances.
* 118 Elements known.
Compounds
• Substances containing 2 or more elements.
“Law of Constant Composition”
The elemental composition of a compound is always the same.
A pure compound has the same “properties” regardless of its source.
Properties: melting point, boiling point, density.
“Mixtures” are combinations of two or more substances.
- Each substance retains its chemical identity and properties.
- The composition of a mixture can vary.
- The “components” are the substances making up a mixture.
Mixtures can be
“heterogeneous” or “homogeneous”
Heterogeneous
• Composition, properties, and appearance vary throughout the sample. e.g., rock, wood.
Homogeneous
- Sample uniform throughout. e.g., air, salt, sugar.
- They can also be called solutions.
- Can be s, l, or g.
Physical Properties include
• M.P, B.P, density, texture, odor, hardness, taste
Chemical Properties include
Describes how something reacts. Flammability and oxidation.
