Transcript Today in Science - Canton Local Schools

Today in Science
You will Need:
1) Pencil, Colored Pencils, Highlighters
or Markers
2) Power Notes – Atomic Structure– 2
page 4 sides-Bookshelf- Please Staple
Topic:
Power Notes- Atomic
Structure
Name
Date
Period
• The concept of “atoms” is believed to
have originated in ancient Greece
with Democritus supporting the idea
that all matter is made up of tiny
particles. It has taken several
hundred years to understand what
we know about the atom today. .
Do we understand
everything????
*NOT EVEN CLOSE!
Democritus 400 BC
Greece - stated that
all matter is made up
of atoms. He also
stated that atoms are
eternal and invisible
and so small that
they can’t be divided,
and they entirely fill
up the space they’re
in
Lavoisier 1789
France - provided the
formula for the
conservation of matter
in chemical reactions,
and also distinguished
between an element
and a compound
• 1st idea of “atoms”
• Believed all matter is made
up of tiny particles separated
by space
• Named particles “atomos”
which means indivisible.
• Founder of modern
chemistry
• 1st carefully controlled
experiments providing
evidence to the Law of
Conservation of Mass
Dalton 1766-1844
England - formed the 1st atomic theory,
which states that all matter is composed of
tiny, indestructible particles called atoms
that are all alike and have the same atomic
weight.
1st MODERN Atomic Theory
1. All matter made up of tiny
indivisible particles called
atoms
2. Atoms of the same element
have identical properties
3. Atoms of different elements
have different properties
4. Atoms combine in a specific
ratio to form compounds
5. A specific compound is
always made up of atoms in
a specific proportion.
Thomson 1897
Plum Pudding Model
1. Negative particles scrambled
into the “dough” of the
positive particles.
England - discovered
the electron and
developed the plumpudding model of the
atom.
Rutherford 1898
England - used the results
of his gold-foil experiment
to state that all the mass
of an atom was in a small
positively-charged ball at
the center of the atom.
Gold Foil Experiment
1. Atoms are mostly empty
space
2. All the Mass of an atom is in
the positively charged ball in
the center of the structure.
Bohr 1922
Denmark - stated that
the electrons moved
around the nucleus in
successively large
orbits. He also
presented the Bohr
atomic model which
stated that atoms
absorb or emit radiation
only when the electrons
abruptly jump between
allowed, or stationary,
states.
Schrödinger (Schroedinger
Austria - introduced the
)1930
Shroedinger Equation, a
wave equation that
describes the form of the
probability waves that
govern the motion of
small particles and how
these waves are altered
by external influences.
“Planetary” atom model
1.
Believed the atom structure was like
our solar system: nucleus in the
middle like the sun and the electrons
orbiting like the planets.
Wave Mechanic Model
1. Planetary model was too specific
2. Rather: electrons vibrate around
the outside of the nucleus- can
only predict where they are most
like to be
3. QUARKS – protons, neutrons and
electrons made up of some of
these smaller particles.
4.
http://library.thinkquest.org/05aug/01087/quarks.html
Basic Atomic Structure
Today scientists agree on the
three basic subatomic particles
that make up all atoms.
Bohr Model for Lithium
Electron = 3
(not to scale)
P= 3 +
N=3 0
Where is most of the mass in the
Atom?
Where is most of the volume in the
Atom?
NUCLEUS
Outside the Nucleus; Electron Cloud
Nucleus
•
•
•
•
Electron
•
•
•
Contains protons(+) and
Neutrons (0)
Holds most of the mass of
the atom
Very small compared to the
entire size of the atom
Most dense part of the atom
Negatively charged
subatomic particle
Found outside the nucleus in
the electron cloud
Smallest particle; mass =
1/1836th of the atom
Proton
•
•
•
•
•
Neutron
•
•
•
•
•
•
Positively charged subatomic particle
Found in the nucleus
Mass = 1 amu (atomic mass unit)
# of protons in an atom IDENTIFIES the
atom (which element)
# of protons in the nucleus of an atom
called the atomic number
Zero charge
Mass = 1 amu
Do NOT affect the identity of the atom
Found in the nucleus
Same atom of an element can have
varying amounts of neutrons (isotope)
Adding the total number of protons &
neutrons = Atomic Mass Number
http://www.sawyerscience.com/Units/unit2/atoms_compounds.html
All atoms found on the •
Periodic Table are
Isotope
•
Neutral – same # of protons(+) and
# of electrons(-)
Atoms of the same element with
same number of protons and
different number of neutrons.
nucleus
Hydrogen has 3 natural
occurring ISOTOPES:
Protium, Deuterium and
Tritium
nucleus
Proton
Protium
nucleus
Deuterium
Neutron
Tritium
Atomic MASS
•
On the Periodic Table represents a
weighted average of the mass of all
naturally occurring isotopes of each
element. (based on mass and
abundance of each isotope).
IONS
•
When atoms gain or lose electrons
they become charged. (number of
protons (+) and electrons (-)
particles are NOT EQUAL)
REVIEW & REFLECT
+
-
Coloring the Periodic
Table
*Textbook pg 196-197 – Use the
key
•
Outline each box in the following
way:
1. Metalloids – in BLUE
2. Nonmetals – in ORANGE
3. Metals – in GREEN
Homework
1)Power Notes– Due by Friday (There
is time to work in class tomorrow)
Do You see HOW the periodic table and the
Atomic Structure are RELATED?