Transcript Welcome to my class - Doral Academy Preparatory

•Big Idea #8: Properties of Matter
•Big #1: Nature of Science
•Essential Content: Atoms,
Elements, & Theories in Science
Illustration From October 2011
Issue of Scientific American
“Atom Power” Article
Key Concepts for this Unit
 Neutral, atom, model, molecule, element,
proton, neutron, electron, nucleus, energy
level, electron cloud, solid, liquid, gas, state,
phase, kinetic energy, change of state,
melting, freezing, evaporation, vaporization,
condensation, sublimation, subatomic
particle, atomic theory, atomic number, mass
number, atomic mass.
Daily Objectives:
 Describe the development of the current model of the
atom.
 Illustrate how and why the model of the atom has
changed over time.
 Differentiate between the building blocks of matter the
atom and building blocks of life the cell.
Essential Questions:
 1. How did Democritus describe atoms?
 2. How did John Dalton further Democritus’ ideas on
atoms?
 3. What instruments are used to observe individual
atoms?
“Would you find it difficult to believe in
something you couldn’t see? Using your
unaided eyes, you cannot see the tiny
fundamental particles that make up matter.
Yet all matter is composed of such particles,
which are called atoms. An atom is the
smallest particle of an element that retains
its identity in a chemical reaction”
(Wilbraham, Staley, & Matta, 2005).
Definition of an Atom
 An atom is the smallest particle of an element that retains
its identity in a chemical reaction.
 Because chemical reactions produce a substance with a
new identity (new physical and chemical properties),
when atoms of the same kind combine to form elements,
the same thing occurs—a new product is formed.
Class Notes:
 Who was Democritus? How
is he involved with the atom?
 He was a Greek philosopher
who started the discovery of
the atom by claiming that
they were the indivisible
building block of matter.
Who is John Dalton?
 John Dalton continued
Democritus’ research by
developing the Atomic
Theory.
 This theory is based off the
4 “rules” that all atoms
follow.
Class Notes: Dalton’s Atomic Theory
1. All elements are made up of atoms that are indivisible.
2. Atoms of the same element are identical.
3. Atoms of different elements combine in ratios to form
compounds.
4. Atoms of one element can never turn into another
element’s atom.
Instrument Used to See the Atoms
 This is called a Scanning
Tunneling Microscope
Electron micrographs showing inactive (left)
and active (right) catalysts consisting of gold
particles absorbed on iron oxide. The red
circles indicate the presence of individual
gold atoms. The yellow circles show the
location of subnanometer gold clusters that
can effectively catalyze the conversion of
carbon monoxide to carbon dioxide. One
nanometer is about half the size of a DNA
molecule. (Color added for clarity) (Credit:
Lehigh University Center for Advanced
Materials and Nanotechnology)
CW: History of the Atom Review
Part 1: Answer questions 1 &2 from the notes
1. Who is Democritus and how is he involved with the
history of the atom?
2. Explain John Dalton’s contribution to the science of the
atom.
Part 2: Read pgs 90-91 in your Reading Essentials Wkbk.
Answer Reading Check questions #3, 4, 5, & 6