Download Chapter 3 notes

Chapter 3 notes
Chapter 3.1 Notes
Atoms- are the smallest complete particle in an
element.
Democritus- Greek philosopher that said the
universe was made up of atoms.
John Dalton- English schoolteacher came up
with the atomic theory in 1808.
1. Every element is made of atoms that can’t be
subdivided.
2. Atoms of the same element are exactly alike
3. Atoms of different elements can join to form
molecules.
• Nucleus- is the center of an atom; it is made up
of protons and neutrons.
• Proton- is a positively charged subatomic
particle in the nucleus of an atom.
• Neutron- is a neutral subatomic particle that is
found in the nucleus of an atom.
• Electron- a tiny negatively charged subatomic
particle that moves around the outside of the
nucleus.
Atomic number of an element is the
number of protons in the nucleus of
each atom of that element.
• The # of protons = the # of electrons
Mass number is the number of protons
and neutrons in the nucleus of an
isotope.
• Mass # = p+ + n
Atomic #
6
Symbol
• SOooo n= Mass # - p+
C
Carbon
Element
12.001
Mass #
Drawing Atoms
Nucleus (center) has 1. element symbol, 2. # of
protons (atomic #) 3. # of neutrons (bottom #
- top #)
Energy Shells have the number of electrons
• Shell #1 can hold 2
• Shell 2-6 can hold 8
Al
P+ 13
N 14
e1
e10
e9
e3
e11
e2
e8
e7
e4
e5
e12
e6
e13
• Orbital- or energy shell/level is a region in
an atom where there is a high probability
of finding electrons.
• Valence electron- an electron in the
outermost energy level of an atom. So in
Al valence 3.
Chapter 3.2 Notes
• Periodic law- properties of elements tend
to change in a regular pattern when
elements are arranged in order of
increasing atomic number, or number of
there protons in their atoms.
Period- a horizontal row of elements in the
periodic table.
Group (family)- a vertical column of elements in
the periodic table.
Ion- an atom or group of atoms that has lost
or gained one or more electrons from and
therefore has a net electric charge.
• Cation- an ion with a positive charge. Na+
• Anion- an ion with a negative charge. O-2
• Atomic number- the number of protons in
the nucleus of an atom.
• Atomic mass- the total number of protons
and neutrons in the nucleus of an atom.
• Isotopes- any atoms having the same
numbers of protons but a different number
of neutrons.
Atomic #
5
B
Boron
10.81
Symbol
Element Name
Mass # or
Atomic Mass
• Atomic mass unit (amu)- a quantity equal
to one-twelfth of the mass of a carbon-12
atom.
• Average atomic mass- the weighted
average of the masses of all the naturally
occurring isotopes of an element.
Notes Chapter 3.3
• Metals- the elements that are good
conductors of heat and electricity.
• Nonmetals- the elements that are usually
poor conductors of heat and electricity.
• Metalloids or Semiconductors- the
elements that are intermediate conductors
of heat and electricity
F
A
NONmetals
M
I
Metals
L
Y
PERIOD
Family or groups- vertical columns (18)
Period- horizontal rows (7)
Metals- Shiny, conduct heat and electricity, can be shaped
Nonmetals- brittle, dull, poor conductor
Metalloids- have some characteristics of metals and nonmetals.
Are semiconductors
Family Names
•
•
•
•
•
•
•
•
•
Family #1- Alkali metals
Family #2- Alkaline-earth metals
Families #3-12 Transition metals
Family #13 Boron’s
Family #14 Carbon’s
Family #15 Nitrogen’s
Family #16 Oxygen’s
Family #17 Halogens
Family #18 Noble Gases
Chapter 3.4 Notes
Mole- the SI the base unit that describes the
amount of substance. (like a dozen)
Avogadro’s constant- the number of particles
in 1 mol; equals 6.022 x 1023 particles.
Molar Mass- the mass in grams of 1 mol of a
substance. (mass # off periodic table)
Conversion factor- a ratio equal to one that
expresses the same quantity in two different
ways. 1 dozen = 12 1 dozen
12
12
1 dozen
• “Atom”. Jan. 7, 2008.
http://www.calstatela.edu/faculty/acolvil/mi
neral/atom_structure1.jpg
• “Periodic Table”. Jan 7, 2008.
http://serc.carleton.edu/images/usingdata/
nasaimages/periodic-table.gif
• “Periodic Table”. Jan 9, 2008.
http://www.elementsdatabase.com/Images
/periodic_table1.gif