Matter A closer look by dffhrtcv3

VIEWS: 3 PAGES: 20

									A toms and Molecules
                2011
Atoms vs. Molecules
 What is the difference between an atom and a
 molecule?
Inquiry: Smaller, smaller, and smaller….
 Observe the rock salt.
 Break the rock salt into smaller pieces. Find the smallest
  piece.
 What kind of change occurred?
 Think for a moment….if you could break the smallest
  particle down into the smallest piece that would still be
  salt:
    Would you be able to see the particle?
    What would you call the particle?
It’s all Greek to me!
 •What is the smallest particle of matter that
 has the same composition as every other
 piece of matter? Atom OR Molecule
 •What is the smallest particle of matter that
 has the same properties as every other
 piece of matter? Atom OR Molecule

 The answer is the same…depending
 on the kind of substance present.
It’s all Greek to me!
We can break a chunk of salt into smaller pieces of
salt that we can see : we would observe the
physical change that takes place.
•These small pieces are still actually quite large to
scientists.
•A single particle of salt may still be composed of
millions of smaller particles of salt.
•If we could break these particles into the smallest
particle of salt that has the same composition and
particles of every particle of salt, we would have a
salt molecule – yet we wouldn’t be able to see it.
Particle
  A general term for any small “piece” of matter.
  It can be regularly shaped like a crystal...




  •Or irregularly shaped like some particles of sand.
  •However, in an effort to mentally picture particles and think
  about what they do, we often picture them or diagram them as
  spheres or circles.
Inquiry-Smaller and smaller and smaller
 Draw a model of a single particle of rock salt, NaCl,
  sodium chloride.

(A molecute of sodium chloride (NaCl) composed of sodium
  and chlorine atoms.)
Take a look!
 A single particle of table salt is a sodium chloride
   molecule.


                Na           Cl

 Composed of one sodium atom and one chlorine
  atom bonded together.
An Atom is the smallest unit of
an element.

                   H      H
Element
Hydrogen
           {   H
                   H     H


           Atom
Take a look!
 These bonds are a strong force of attraction.


    Na     Cl  Na              Cl     Na         Cl
          Na Cl
                                           Na         Cl
 ……..A bond that is so strong that is cannot be
  broken down by physical changes or even common
  chemical changes like burning (combustion)
AMOLECULE                is the smallest unit of a
compound that retains the chemical characteristics of
the compound.
 Composition of molecules is given by a
   MOLECULAR FORMULA
       H2O                    C8H10N4O2 - caffeine




                         NaCl


                   Na       Cl
Inquiry-Smaller and smaller and smaller
 How many individual NaCl molecules do you think
 one grain of salt contains?
 a. one molecule
 b. 10 molecules
 c. 1,000 molecules
 d. At least a million molecules
Quick Quiz
1. Matter is made up of particles. The smallest particles are
   either ___________ or ____________.
2. Sodium is a(n) __________(a type of substance) composed
   of like ___________ (particles).
3. Sodium chloride in a(n) _____________(a type of
   substance) composed of atoms (types of particle) of
   different _____________(types of pure substances).
4. Sodium chloride can be broken down into sodium and
   chlorine through ___________changes.
 Imagine going to an ice cream store. Let's say that they
 have 30 different flavors of ice cream. Those are
 elements, the things that I have available to build my
 dessert from. The smallest amount of ice cream that
 the store will sell to me is a scoop. This is an atom. If I
 want, I can put two or more scoops of ice cream
 together. This is a molecule. If my molecule has more
 than one flavor of ice cream, I can call it a compound.
So in Summary……..
 element - a basic substance that can't be simplified
  (hydrogen, oxygen, gold, etc...)
 atom - the smallest amount of an element
 molecule - two or more atoms that are chemically
  joined together (H2, O2, H2O, etc...)
 compound - a molecule that contains more than one
  element (H2O, C6H12O6, etc...)
Using models to visualize matter too small for us to see. Integrating two
concepts: particles and substances. Describe every diagrams as completely
as possible.

 Particle(s)?             Model                            Pure substances(s)?
 atom(s) or molecule(s)                                    element(s) or compound(s)

                                               H


 Two individual atoms
                                                       H
                               H

                                           H       H       One element-hydrogen

                                   H                   H

                                               O




                                       O               O


 Two individual atoms                                      One element-oxygen
How do scientists use model particles?

Particles are represented using
single individual, disconnected
circles or…
Seeing the same colors can
mean that…
Different size circles can show
us that…

Different labels (chemical
symbols)can show us that…
Circles are joined to show us
that…
Pure Substances vs. Mixtures
              Pure substance
              composed of individual
              atoms of one type of
              element.

              Mixture composed of
              individual atoms of one
              type of element and
              molecules of a different
              element.
Pure Substances vs. Mixtures
              Pure substance
              composed of individual
              molecules of one type of
              compound



              Mixture composed of
              individual atoms of one
              type of element and
              molecules of a different
              element.
Mixture composed of
individual atoms of two
different elements




A mixture composed of
molecules of one element
and molecules of one
compound.

								
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