Chapter 1 Flashcards
Atoms
Submicroscopic particals that constitue the fundamental building blocks of ordinary matter
Molecules
specific geometrical arrangements of atoms
Chemistry
the science that seeks to understand the behavior of matter by studying the behavior of atoms and molecules
hypothesis
tentative interpretation or explanation of observations. A good one is falsifiable
experiments
highly controlled procedures designed to generate observations that may confirm or refute a hypothesis
Scientific Law
Brief statement that summarizes past observations and predicts future ones
law of conservation of mass
In a chemical reaction matter is neither created nor destoryed
Theory
One or more well-established hypotheses may for the basis for a theory. A model for the way nature is and tries to explain not only what nature does but why.
Atomic Theory
Proposed by John Dalton
Matter
anything that occupies space and has mass
substance
a specific instance of matter. ex. air, water, sand
state
A way of classifying matter by its physical form
Composition
the basic components that make it up
Three different states of matter
solid, liquid, gas
Solid matter atoms or molecules…
pack close to each other in fixed locations. Fixed volume and shape.
crystalline solid matter
atoms or molecules are arranged in patters with a long, repeating range and order. ex. salt
Amorphous solid matter
atoms or molecules do no have any long range order. ex glass or plastic
Liquid matter
atoms or molecules pack about as closely as they do in solid matter, but they are free to move relative to eachother. Fixed volume, not shape
Gaseous Matter
atoms or molecules have alot of space between them and are free to move relative to one another, making them compressible. No fixed volume or shape
Pure Substance
Made up of only one component and its composition is invariant
Mixture
Composed of two or more components in proportions that can vary from one sample to the other
Types of pure substances
Elements and compounds
Element
a substance that cannot be chemically broken down into simpler substances
Compound
a substance composed of two or more elements in a fixed, definite proportion
Types of mixtures
heterogeneous and homogeneous
Heterogeneous Mixture
the composition varies from one region of the mixture to another
Homogeneous Mixture
same composition throughout
Separating mixtures
decanting, distillation, filtration
Decanting
carefully pouring off the the liquid into another container. Heterogeneous mixtures
Distillation
Process in which the mixture is heated to boil of te more volatile liquid. Homogeneous
volatility
ease of vaporization
Filtration
the mixture is poured through a filter paper in a funnel. Heterogeneous
Physical changes
changes that alter only stat or appearance but not composition. ex. boiling water changes from liquid to gas
Chemical change
atoms rearrange, transforming the original substances into differant substances. ex. rusting iron
Physical property
substance displays without changing is composition
chemical property
substance displays only by changing its composition via chemical change
Energy is
the capacity to do work
Work is
as the action of a force through a distance
kinetic energy
energy associated with motion
potential energy
energy associated with its position or composition
thermal energy
energy associated with the temperature of an object
law of conservatoin of energy
energy is neither created nor destroyed, only changes form
Units
standard quantities used to specify measurements
Kelven to Celsius
K = C + 273.15
Celsius to fahrenheit
C = (F - 32) / 1.8
Prefix multipliers
Change the value of units by powers of 10
derived unit
combination of other units. ex. miles/hour
volume
a measure of space
1 milliliter =
1 cm^3
density
the ration of its mass to its volume
density formula
d = m / v
intensive property
independent of the amount of substance
extensive property
dependent on the amout of the substance
significant figures (significant digits)
non place holding digits
exact numbers
have no uncertainty and do not limit the number of significant figures in a calculation
Accuracy
how close the measured value is to the actual value
precision
how close a series of measurements are to one another, and how reproducible they are.
random error
error that has equal probability of being to high or too low. Enough trials should even it out.
systematic error
error that tends toward being either too high or too low. Will not even itself out
dimensional analysis
Using units as a guide to solving problems
conversion factor
fractional quantity with the units we are converting from on the bottom and the units we are converting to on the top.
