1. Simplest form of matter
2. Distinct chemical and physical properties
3. Cannot be broken down chemically into simpler, stable substances
Elemet
The smallest amount of an element that still has the characteristics of that element
Atom
Pure Substances
Elements and compunds
Mixture
Two or more substances that are physically combined
Mixtures:
Not chemically bonded
Can be separated by physical means
do not have definite competitions
Heterogeneous mixture
Substance not uniformly mixed
Homogeneous mixture
Has Uniform Composition
(uniformly mixed)
Describe a substance without changing composition
Physical Properties
Characteristic chemical reactions that chemical undergoes (changes competition)
Chemical Properties
Extensive Properties depend on:
The amount of a substance
Ex. Mass, Volume
The same regardless of mass
Ex. Density, Color, melting point
Intensive Properties
Constant and typically different from the properties of elements that compose them
Ex. Sodium, reactive t water, Sodium Chloride not reactive
Properties of Compounds
Similar to the properties of compounds of the mixture and changes based of amount of compounds
Properties of mixtures
Physical change
When the composition of a substance is not altered
Chemical change
Reactions rearrange chemical composition to form products
Refers to the identity of form of quality of a substance
Qualitative Data
Quantitative Data
Determines the amount of the substance (quantity)
Precision
Closeness of all of a set of measurements to one another
Accuracy
Closeness of average of a set of mesurments to the true value