Ch. 1 Flashcards
Science
Knowledge gained through experience or experiment (empirical knowledge)
Chemistry
The study of matter and its interactions with other math and with energy
Scientific Method
Investigations that are guided by theory and earlier experiments
Hypothesis
A possible explanation for an event
Law
A statement that summarizes a large number of observations
Theory
An explanation of the laws of nature
Matter
Anything that has mass and occupies space
Mass
The quantity of matter in an object
Weight
The force of attraction between an object and other objects
Property
Anything observed or measured about a sample of matter
Extensive Property
Depends on the size of the sample (mass, volume)
Intensive Property
Independent of size sample (density, color, melting point, boiling point)
Physical Properties
Can be measured without changing the composition of the sample (mass, density, color, melting point)
Physical Change
A change that occurs without changing the composition of the material (freezing, melting)
Chemical Properties
Describe the reactivity of a material (methane burns in air)
Chemical Change
At least part of the material is changed into a different kind of matter (burning methane in air produces carbon dioxide and water)
Substance (Classification of Matter)
A material that is chemically the same throughout
Elements (type of substance)
Cannot be broken down into simpler substances
Compounds (type of substance)
Can be broken down into elements
Mixture (Classification of Matter)
Matter than can be separated into simpler materials by physical methods
Heterogeneous Mixtures
The composition of the mixture changes from one part to another (rocks)
Homogeneous Mixture (Solutions)
The composition of the mixture is uniform throughout (air)
Alloys
Solutions of a metal and another material - usually another metal (brass)
Accuracy
The agreement of a set of measurements with the true value
