1-2 Essential Ideas Flashcards
What is an element?
A substance composed of a single type of atom, cannot be broken down further. (Copper,gold,iron)
What is a compound?
A pure substance that can be decomposed into 2 or more elements (water, table salt)
What is the Law of conservation of matter?
Matter can neither be created or destroyed
What are atoms?
The smallest particle of an element that can enter into a chemical combination.
What is a molecule?
2 or more atoms joined by chemical bonds
Extensive property
Property that depends on the amount of matter present (mass/volume)
Intensive property
Property that does NOT depend on amount of matter present (temperature)
Heterogeneous mixture
Mixtures with compositions that change from point to point (water & oil, milk & cereal, concrete mixing)
Homogeneous mixture
(solution)
Mixtures with uniform compositions and appear visually the same (coffee, milk, air)
What is a hypothesis
Tentative explanation of observations that act as a guide for gathering and checking info
What is a law?
Statement that summarizes a vast number of experimental observations and describes some aspect of the world
What is a theory ?
Well substantiated comprehensive testable explanations of parts of nature
What are the 3 domains of chemistry?
Macroscopic (large everyday realm), microscopic (super small), symbolic (special language of chemistry -symbols, formulas, equations ect.)
Gas
Has no definite volume or shape, expands to fill container
Liquid
Has definite volume, but indefinite shape