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## Ignore words

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quantitative measurements
has a magnitude, size or amount (need units)
based off metric system (mKsK)
international system of units (SI system)
D=
(n*MM)/V
units of density
g/mL or g/cm3 (cubed)
does not depend on size
A characteristic physical property of a susbstance
accuracy
A description of how close a measurement is to the true value of the quantity measured.
precision
closeness to a set of measurements of the same quantity madeht same way
metric prefix scale
king henry died drinking chocolate milk
the number is large
in scientific notation what does a positive exponent mean
the number is small
in scientific notation what does a negative exponent mean?
dmitri mendeleev
henry moseley
noticed a "new" pattern on the periodic table
Atomic Number
A unique number for each element on the periodic table that is equal to the number of protons in any atom of that element. 2. The elements Identity
Atomic mass
A relative mass determined by means of a standard
periodic law
physical and chemical properties of the elements are a periodic function of their atomic numbers (number of protons in the nucleus); -elements with similar properties occur at regular and predictable intervals (medeleev)
the abbreviation of the element name
what is the symbol on a periodic table
what is atomic weight?
average of the mass of each of the isotopes based on their percent abundance
number of electrons
atomic number (if NEUTRAL) atom only
Number of Neutrons
Found by subtracting the Atomic Number from the Mass Number
mass number
Sum of protons and neutrons
isotopes
atoms of the same element that have different masses: the same protons, but different neutrons -same chemical properties
protium- h1
isotopes of hydrogen
Molar Mass
mass in grams of 1 mol of a substance
mole
_______is the amount of a substance that contains the same number of particles as the number of atoms in 12 g of carbon-12. That would be 6.02 x 10 23 atoms.
6.022x10^23
= 1 gram
why don't we work with individual atoms or molecules
because they are too small to be weighed of measured
why do we measure in moles
because we have to work with lots of atoms in order to measure them
Democritus
(460-370 BCE) A Greek philosopher who theorized that all matter could be reduced to particles that could not be divided, which he described as "atomos."
Aristotle
A Greek that stated that all matter is made up of four elements: earth, air, fire, and water.
atoms theory
gained experimental evidence in the 17th century to support this theory
john dalton
ancient school teacher
dalton's atomic theory
all matter is composed of extremely small particles called atoms
modern atomic theory
atoms are divisible, into subatomic particles
jj thomas
discovered the electron-negatively charged smaller particles in an atom; knew that atoms were neutral, but could not find the positive particle
cathode ray tube experiment
determined that electrons are negatively charged
Plum pudding
The atom is a small mass of positive matter with negatively charged particles
robert millikan
oil drop experiment
Ernest Rutherford
Discovered the nucleus in 1911 with his now famous gold foil experiment
atomic structure
atoms are composed of small particles
what is a physical change in a substance
a change in a substance that does not involve a change in the identity of the substance
chemical changes in a substance
a change in a substance that involves a change in the identity of the substance
classification of matter
pure substance, mixture,
pure substance
A sample of matter, either a single element or a single compound, that has definite chemical and physical properties
Homogeneous
A mixture in which all the individual substances are evenly mixed throughout.
Heterogeneous
A mixture in which one or more substances are unevenly mixed.
What is an element?
An element is a substance that is made up of only one type of atom.
What is a compound?
A compound is a substance that is made up from two or more different types of atom chemically bonded together.
What is a mixture?
A mixture is a substance that is made up from two or more different types of atom NOT chemically bonded together.
On the left hand side of the periodic table.
Where would you find the metals in the periodic table?
Protons & neutrons
What two sub-atomic particles are found in the nucleus?
In shells around the nucleus
Where would you find the electrons in an atom?
Protons = positive (+)
What are the relative charges for the sub-atomic particles - protons, electrons & neutrons?
Proton = 1
Give the relative mass for each sub-atomic particle.
Why does an atom have no overall charge?
An atom has the same number of positive protons and negative electrons - their opposite charges cancel out.
P = 3
Calculate the numbers of protons, electrons & neutrons inside of a LITHIUM ATOM.
P = 19
Calculate the numbers of protons, electrons & neutrons inside of a POTASSIUM ATOM.
1st shell = 2 electrons
How many electrons fit into the first 4 shells of an atom before they get full up?
What do all elements within the same group have in common with each other (in terms of electrons)?
All elements within the same group have the same number of electrons on the outside shell (eg. group 1 elements have 1 electron on the outside shell)
Name of group 0 elements and why grouped together
Nobel gases - all unreactive due to having a full outer shell
Ionic bonding
Bonding between metals and nonmetals
Covalent bonding
Bonding between nonmetals
molecule
2 or more atoms of same or different kinds that are chemically combined.
Protons
Atom Structure
Neutrons
neutral subatomic particle
electrons
the highest energy of level of metals contain few
atomic weight
# of protons and neutrons
ions
at the anode, atoms become
unstable isotopes that emit subatomic particles and radiation
chemical bonds
2 or more atoms bind together
ionic bonds
form from the attraction of oppositely charged ions.
covalent bonds
atoms share pairs of electrons
hydrogen bonds
attraction between molecules that have hydrogen bonded to a small, high en atom
catabolism
breaking down of molecules, releases energy
anabolism
the synthesis of larger molecules, requires energy.
polar compound
molecules joined by asymmetrical polar bonds.
surface tension
a measure of how difficult it is to break the surface of a liquid