Chemistry Midterm

Matter
anything that has mass and occupies space
Chemistry
the study of the composition of matter and the changes that matter undergoes
the five traditional areas of study
organic
inorganic
biochemistry
analytical
physical
Organic Chemistry
the study of all chemicals containing carbon
Inorganic Chemistry
the study of chemicals that in general do not contain carbon
Biochemistry
the study of processes that take place in organisms
Analytical Chemistry
the area of study that focuses on the composition of matter
Physical Chemistry
the area that deals with the mechanism, rate, and the energy transfer that occurs when matter undergoes a change
Pure Chemistry
the pursuit of chemical knowledge for its own sake
Applied Chemistry
research that is directed toward a practical goal or application
Technology
the means by which a society provides its members with those things needed and desired
Macroscopic world
the world of objects that ore large enough to see with the unaided eye
Microscopic world
the world of objects that can only bee seen under magnification
Biotechnology
applies science to the production of biological products or processes
Pollutant
a material found in the air water or soil that is harmful to humans or other organisms
Lavoisier
French scientist who helped transform chemistry from a science of observation to a science of measurement
Scientific method
logical systematic approach to the solution of a scientific problem
steps in the scientific method
making observations
testing hypotheses
developing theories
Observation
when you use your senses to obtain information
Hypothesis
a proposed explanation for an observation
Experiment
a procedure that is used to test a hypothesis
Manipulated Variable
the variable that is changed during the experiment
Responding Variable
the variable that is observed during the experiment
Theory
a well-tested explanation for a broad set of observations
Scientific Law
a concise statement that summarizes the results of many observations and experiments
Steps for solving a numeric word problem
analyze
calculate
evaluate
Volume
measure of the amount of space occupied by an object
Extensive Property
a property that depends on the amount of matter in sample
Intensive Property
a property that depends on the type of matter in a sample
Substance
matter that has a uniform a definite composition
Physical Property
a quality or condition of a substance that can be observed or measured without changing the substance’s composition
Solid
a form of matter that has a definite shape and volume
Liquid
a form of matter that has an indefinite shape, flows, yet has a fixed volume
Gas
a form of matter that takes both the shape and volume of its container
Vapor
describes the gaseous state of a substance that is generally a solid or liquid at room temperature
Mixture
a physical blend of two or more components
Heterogeneous mixture
a mixture in which the composition is not uniform throughout
Homogeneous mixture
a mixture in which the composition is uniform throughout
Solution
another name for a homogeneous mixture
Phase
used to describe any part of a sample with uniform composition and properties
Filtration
the process that separates a solid from the liquid in a heterogeneous mixture
Distillation
one way to separate water form the other components in tap water
Element
the simplest form of matter that has a unique set of properties
Compound
substance that contains two or more elements chemically combined in a fixed proportion
Chemical Change
a change that produces matter with a different composition than the original matter
Chemical Symbol
one or two letter
Chemical Property
the ability of a substance to undergo a specific chemical change
Chemical Reaction
one or more substance change into one or more new substances
Reactant
a substance present at the start of the reaction
Product
a substance produced in the reaction
Precipitate
a solid that forms and settles out of a liquid mixture
Law of conservation of mass
states that in any physical change or chemical reaction, mass is conserved. Mass is neither created nor destroyed
Measurement
a quantity that has both an number and a unit
Scientific notation
a given number is written as the product of two numbers: a coefficient and 10 raised to a power
Accuracy
the measure of how close a measurement comes to the actual or true value of what is measured
Precision
the measure of how close a series of measurements are to one another
Accepted value
the correct value based on reliable references
Experimental value
the value measured in the lab
Error
the difference between the experimental value and the accepted value
Percent error
absolute value of the error divided by the accepted value, multiplied by 100
Significant figures
include all the digits that are known, plus the a last digit that is estimated
International System of Units
a revised version of the metric system
the 5 SI base units
meter, kilogram, kelvin, second, mole
Meter
(m) basic unit of length
Liter
a more convenient unit of volume, the volume of a cube that is 10 cm along each edge
Kilogram
the basic SI unit of mass,
Weight
a force that measures the pull on a given mass by gravity
Temperature
a measure of how hot or cold an object is
Celsius scale
sets the freezing point of water at 0 degrees and the boiling point at 100
Absolute zero
0 kelvin, or -273 degrees Celcius
Converting between Kelvin and Celsius
K=C+273
C=K-273
Energy
the capacity to do work or produce heat
Joule
the SI unit of energy
Calorie
the quantity of heat that raises the temperature of one gram of pure water by one degree Celsius
Conversion factor
a ratio of equivalent measurements
Dimensional Analysis
a way to analyze and solve problems using the units, or dimensions, of the measurements
Density
the ratio of the mass of an object to its volume
Density= mass/volume
Atom
the smallest particle of an element that retains its identity in a chemical reaction
Dalton’s Atomic Theory
1. all elements of tiny indivisible particles called atoms
2. atoms of the same element are identical. the atoms of any one element are different from those of any other element
3. atoms of different elements can physically mix together or can chemically combine in simple whole-number ratios to form compounds.
4. chemical reactions occur when atoms are separated, joined, or rearranged. atoms of one element, however, are never changed into atoms of another element as a a result of a chemical reaction
Electrons
negatively charged subatomic particles, located outside the nucleus
Cathode Ray
glowing beam of negatively charged electrodes that J.J. Thomson used in his experiment
Protons
positively charged subatomic particles, relative mass of 1, located in the nucleus
Neutron
subatomic particles with no charge, relative mass of 1 (nearly equal to that of a proton), located in the nucleus
Nucleus
the tiny central core of the atom composed of protons and neutrons
Atomic Number
the number of protons in the nucleus of an atom
Mass Number
the total number of protons and neutrons in an atom
Atomic Mass Unit
(amu) defined as one-twelfth the mass of a carbon-12 atom
Atomic Mass
the weighted average mass of the atoms in a naturally occurring sample of the element
Periodic Table
an arrangement of elements in which the elements are separated into groups based on a set of repeating properties
Period
each horizontal row of the periodic table
Group
each vertical column of the periodic table
Energy levels
the fixed energies an electron can have
Quantum
the amount of energy required to move an electron from one energy level to another
Quantum Mechanical Model
the modern description of the electrons in an atom, from the mathematical solutions to Schrodinger’s equation
Atomic orbital
often thought of as a region of space in which there is a high probability of finding an electron
Electron configurations
the ways in which electrons are arranged in various orbitals around the nuclei of atoms
Aufbau principle
electrons occupy the orbitals of lowest energy first
Pauli exclusion principle
an atomic orbital may describe at most two electrons
Hund’s rule
states that electrons occupy orbitals of the same energy in a way that makes the number of electrons with the same spin direction as large as possible
Amplitude
the wave’s height from zero to crest
Wavelength
the distance between the crests of a wave
Frequency
the number of wave cycles to pass a given point per unit of time, usually cycles per second
Hertz
the SI unit of cycles per second
Electromagnetic radiation
includes radio waves, microwaves, infrared waves, visible light, ultraviolet waves, X-rays, and gamma rays
Spectrum
different frequencies of light separated, example is a rainbow
Atomic emission spectrum
the frequencies of light emitted by an element separate into discrete lines
Ground state
when the electron has its lowest possible energy
Photons
light quanta
Heisenberg uncertainty principle
states that it is impossible to know exactly both the velocity and the position of a particle at the same time
Periodic law
when elements are arranged in order if increasing atomic number, there is a periodic repetition of their physical and chemical properties
Metals
are good conductors of heat and electricity, have high luster, solids at room temperature (except for mercury), ductile, and malleable
Nonmetals
poor conductors of heat and electricity, tend to be brittle
Metalloids
generally has properties that are similar to those of metals and nonmetals, under some conditions it may behave like a metal, under some it may behave like a nonmetal, the behavior often can be controlled by changing the conditions
Alkali metals
the group 1A elements
Alkaline earth metals
the group 2A elements
Halogens
the nonmetals of group 7A
Noble gases
the elements in Group 8A, sometimes called the inert gases because they rarely take part in a reaction
Representative elements
groups 1A through 7A, display a wide range of physical and chemical properties, their group number equals the number of electrons in the highest occupied energy level
Transition metal
the highest occupied s sublevel and a nearby d sublevel contain electrons
inner transition metals
the highest occupied s sublevel and a nearby f sublevel generally contain electrons