Chapter 1 - Chemistry - The Study of Change Flashcards
Chemistry
Study of matter and the changes it undergoes
Scientific Method
A systematic approach to research
Qualitative
Consisting of general observation about the system
Quantitative
Comprising of numbers obtained by various measurements of the system
Hypothesis
A tentative explanation for a set of observations
Law
A concise verbal or mathematical statement of a relationship between phenomena that is always the same under the same conditions
Theory
A unifying principle that explains a body of facts and/or those laws that are based on them
Matter
Anything that occupies space and had mass
Substance
Form of matter that has a definite (constant) composition and distinct properties
Mixture
Combination of two or more substances in which the substances retain their distinct identities
Homogeneous mixture
The composition of the mixture is the same throughout
Heterogeneous mixture
Composition is not uniform
Element
Substance that cannot be separated into simpler substances by chemical means
Compound
Substance comprised of atoms of two of more elements chemically united in fixed proportions
Physical property
Can be measured and observed without changing the composition or identity of a substance
Chemical property
To observe this property we must carry out a chemical change
Extensive property
Depends on how much matter is being considered
Mass
Quantity of matter in a given sample of a substance
Volume
Length cubed
Intensive property
Does not depend on how much matter is being considered
Density
Mass of an object divided by its volume d=m/v
Macroscopic properties
Can be determined directly
Microscopic properties
On atomic or molecular scale, must be determined by an indirect method
International System of Units (SI)
Revised metric system
Weight
The force that gravity exerts in an object
Liter
The volume occupied by one cubic decimeter
Kelvin + temp conversions
The SI base unit for temperature m. Absolute temp scale
C=(F-32) (5/9)
F= (9/5)C +32
K= (C+273.15C)
Significant figures
Meaningful digits in a measured or calculated quantity
Accuracy
How close measurement is to true value of quantity that was measured
Precision
How closely two or more measurements of same quantity agree with one another
