85 terms

Review Set #1

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Terms in this set (...)

matter
Anything that has mass and occupies space
kinetic energy
movement of particles, measured by checking the temperature
intermolecular forces
forces of attraction between molecules
solid
In this state of matter the particles are tightly packed together. They vibrate. The colder it gets the closer together the molecules get and the less they vibrate. This state of matter holds its own shape.
liquid
the particles flow easily around one another, and kept from flying apart by the attractive forces between them, assuming the shape of their containers
gas
these particles fly in all directions at great speeds...they are so far apart, the attractive forces are insignificant
plasma
at very high temperatures atoms lose their electrons, the mixture of nuclei and electrons results in this state of matter
incompressible
Incapable of being squeezed into a smaller volume
compressible
capable of being made more compact/taking up less space
entropy
disordered, random
physical property
Any characteristic of a material that can be observed or measured without changing the composition of the substances in the material
extensive
depends on amount
intensive
a quality of a substance that does not depend on amount
physical change
sample changes, bonds do not
chemical property
A characteristic of a pure substance that describes its ability to change into different substances, meaning it breaks or forms bonds
chemical change
means bonds bond or break to form new substances
pure substance
Matter that always has exactly the same composition
mixture
a combination of two or more substances that are not chemically combined
compound
a substance made up of atoms of two or more different elements joined by chemical bonds
element
A pure substance made of only one kind of atom
homogeneous mixture
a mixture that is uniform in composition; components are evenly distributed and not easily distinguished.
heterogeneous mixture
A mixture that is not uniform in composition; components are not evenly distributed throughout the mixture
macroscopic level
matter large enough to be seen, measured and handled
molecular level
what you can't see, but can imagine
chemistry
the study of matter and the changes it undergoes
matter
Anything that has mass and occupies space
element
A pure substance made of only one kind of atom
chemistry
the study of the composition of matter and the changes it undergoes
atom
smallest unit of matter that retains the properties of an element
neutron
subatomic particle that has no charge and that is found in the nucleus of an atom
proton
subatomic particle that has a positive charge and that is found in the nucleus of an atom
electron
subatomic particle that has a negative charge
Democritus
What Greek originally proposed the idea of atoms?
law of constant composition
Atoms combine in whole ratios to make compounds
Dalton
Five ideas about atoms...
1. All matter is made of atoms
2. All atoms of given element are identical
3. The atoms of one element are different from other elements
4. Atoms combine in whole ratios to make compounds: LAW OF CONSTANT COMPOSITION
5. In chemical reactions atoms are separated, combined, or rearranged. (but cannot be destroyed)
J.J. Thompson
found that atoms have particles that move AWAY from the negative end of a magnet, so they must have a negative charge!
William Thompson
He knew that electrons have a negative (-) charge but atoms are neutral (no charge), therefore there must be a positive (+) charge too--which he recognized as protons
Niels Bohr
physicist who worked with Rutherford and proposed that electrons surround the nucleus in specific energy levels or shells
Erwin Schrödinger
developed the quantum mechanial model of the atom
cathode ray tube
...
oil drop experiment
helped determine the mass and charge of a single electron
Millikan
used the "oil drop experiment" to determine the mass and charge of a single electron
Plum pudding model
model of an atom in which electrons were randomly distributed within a positively charged cloud
gold foil experiment
experiment that led to the discovery of the nucleus as the small, dense, positively charged center of the atom
Bohr model
model of an atom that shows electrons in circular orbits around the nucleus
Quantum mechanical model (electric cloud model)
model in which an orbital is a region of space around the nucleus defined by the probability of finding an electron in that region of space, specific 3-D pathways with specific shapes, called orbitals. and predicts where an electron is likely to be 90% of the time
amu
atomic mass unit (a very small measurement of mass that is used to talk about subatomic particles, specifically protons and neutrons)
Ernest Rutherford
having done the gold foil experiment, he realized that atoms must have a VERY small positive central core (nucleus) , and the rest of the atom 99.999% is empty space.
nucleus
dense center of atom
atomic number
Number of protons
mass number
Protons + neutrons
Bohr model
model of an atom that shows electrons in circular orbits around the nucleus
chemical symbol
A one or two letter representation of an element. The first letter is always capitalized (if there is one, the second letter is not).
isotope
atoms of the same element that have different numbers of neutrons
atomic mass
the average mass of all the isotopes of an element
atoms
the smallest unitt of an element having the chemical properties of the element
element
A pure substance made of only one kind of atom
chemistry
the study of the composition of matter and the changes it undergoes
metals
Conductors of heat and electricity, malleable, ductile (can be pulled into wires), lustrous (shiny)--example: gold
metalloids
found along the staircase, has properties of both metals and nonmetals, tend to be good semiconductors--example: silicon
nonmetals
low boiling points, brittle, dull, good insulators--example: sulfur
atom
smallest unit of matter that retains the properties of an element
neutron
subatomic particle that has no charge and that is found in the nucleus of an atom
proton
subatomic particle that has a positive charge and that is found in the nucleus of an atom
electron
subatomic particle that has a negative charge
amu
atomic mass unit (a very small measurement of mass that is used to talk about subatomic particles, specifically protons and neutrons)
nucleus
dense center of atom
Noble Gases
Elements in group 8A of the periodic table. Have no charge, unreactive with the exception of radon, and are gases under normal conditions. (Helium, Neon, Argon, Krypton, Xenon, Radon)
Halogens
contains nonmetals, 7 valence electrons in it's outermost energy level, very reactive
conductors
materials that transfer energy easily
malleable
can be hammered flat
ductile
can be pulled out into a long wire.
lustrous
shiny
periodic table
a chart of the elements arranged into rows and columns according to their physical and chemical properties, showing the repeating pattern of their properties; first was arranged by ATOMIC MASS (Mendeleev), then by ATOMIC NUMBER and PROPERTIES (modern)
atomic number
the number of protons in the nucleus (never changes)
atomic symbol
A one or two letter abbreviation for an element
atomic mass
average mass of all the isotopes of an element
7 periods
horizontal rows on the periodic table
8 major groups
(families)- vertical columns whose elements have similar properties; 18 groups altogether
transition metals
groups 3-12, center of the periodic table
actinids and lanthanoids
aka the inner transition metals; form a group that appears almost disconnected from the rest of the periodic table.
Alkali Metals
soft metals that are extremely reactive; group 1A
Alkali Earth Metals
shiny reactive metals; Group 2A
melting point
Temperature at which a solid becomes a liquid
boiling point
The temperature at which a liquid changes to a gas