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Atoms, Elements, Compounds, Molecules,

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Atoms, Elements, Compounds,
Molecules, & Mixtures
Notes
Activating Strategy
Let’s See What you Know…
In our previous lesson we
learned that the pencil is
matter
made of ______?
If you look closely at the tip of a
sharpened pencil, you will see
that it is made of a specific type
of matter called graphite.
The image shows a close up
picture of the graphite. The
graphite is made up of even
smaller particles called atoms
_____.
These particles contain even
smaller particles called
protons,
neutrons, electrons
_____________________
How are atoms,
molecules, elements,
compounds, &
mixtures related?
Standard: S8P1a. Distinguish
between atoms and molecules, as
well as pure substances (elements
and compounds) and mixtures
Adapted from www.middleschoolscience.com 2008
How is
matter
classified?
Matter
Pure
Substance
Element
Mixture
Compound
Matter is anything that has mass and
takes up space (volume)
There are different types of Matter:
Pure Substances (elements and
compounds) and Mixtures
The composition (structure) of a
substance determines its Matter type.
Characteristics of Pure Substances
• Fixed composition
• Distinct properties
• Cannot be separated into simpler
substances by physical methods
• Can only be changed in identity and
properties by chemical methods
• Properties do not vary one sample to
another sample
• Types of Pure Substances: Elements &
Compounds
Image are from http://www.chem4kids.com
•A small particle that
makes up Matter
•Consists of Protons (+),
Electrons (-), and Neutrons (N)
How big is an atom?
www.scaleofuniverse.com
• Consists of only one kind of atom.
• Cannot be broken down into a
simpler type of matter.
•Examples: Gold, Helium,
Hydrogen, Uranium, Lithium
• A molecule consists of two or more
atoms of the same element, or different
elements, that are chemically bound
together.
• In the animation above, two nitrogen
atoms (N + N = N2) make one Nitrogen
molecule .
Compounds
• Form when two or more
different elements join (bond)
together chemically
• Composition is identical in each sample
• Can be separated only by chemical methods
• Properties of a compound are totally
different than the properties of the elements
that form them
• Examples: Water, Carbon dioxide, Salt
Animated images and notes from http://www.chem.purdue.edu/gchelp/atoms/elements.html
Cl
Na
Compounds
What’s the difference between
a molecule and a compound?
Watch the video!
https://www.youtube.com/watch?v=0gsrW0Vb5sw
A molecule is formed when two or more
atoms join together chemically. A
compound is a molecule that contains at
least two different elements. All
compounds are molecules but not all
molecules are compounds.
Elements and Compounds
Study Jams Video
http://studyjams.scholastic.com/studyjams/jams/sc
ience/matter/elements-and-compounds.htm
Mixtures
• Form when elements and/or compounds
are combined physically
• Properties of a mixture are related to its
components
• Composition varies from sample to sample
• Can be separated by physical methods
• Examples of Mixtures: Tea, Perfume, Air,
Salad, Beach sand, oil and vinegar salad
dressing, etc.
Mixtures
Mixture of
Different Elements
Mixture of Different
Compounds
Mixtures
Mixtures are often referred to
as homogeneous or
heterogeneous.
Mixtures
• Homogeneous mixtures (Solutions) have
a uniform distribution.
• For example: Tea, Perfume, Air
Mixtures
• Heterogeneous mixtures
do not have a uniform
distribution.
• Parts are often visible
• For example:
Salad, Beach Sand,
Oil and Vinegar dressing
Mixtures Study
Jams Video
http://studyjams.scholastic.com/studyja
ms/jams/science/matter/mixtures.htm
Distinguishing between Elements,
Compounds, and Mixtures
Distributed Summarizing
The diagram below shows how two elements can be mixed
together…Which is a Compound? A Mixture?
C.
A.
B.
D.
Match the Picture to the Description
Compound of 2
Elements
Mixture of Molecules
Element Molecule
Compound of 3
Elements
Element/ Atoms
Mixture of Atoms
Match the Picture to the Description
Compound of 2
Elements
Mixture of Molecules
Element Molecule
Compound of 3
Elements
Element/ Atoms
Mixture of Atoms
A Chemical Formula is a representation of a
substance using symbols for its essential
elements.
Counting elements
in a molecule
• Count the number of
different capital letters
or element symbols in
the compound.
© KeslerScience.com
A Chemical Formula represents in symbols and
numbers the amount of atoms in a specific type
of matter.
Let’s examine a few Chemical Formulas.
H2O = Water
How many atoms are there in H2O? How
many elements?
There are 2 elements (Hydrogen & Oxygen). There
are 2 Hydrogen Atoms and 1 Oxygen Atom
A Chemical Equation is a symbolic
representation of what happens when
atoms react with each other
Review: What is the Law of Conservation
of Matter?
The Law of Conservation of Matter
[Mass] states that matter cannot be
created or destroyed. It changes form.
A Chemical Equation can
illustrate the Law of
Conservation of Matter.
Let’s see how
Law of Conservation of Matter [Mass]:
The Mass of the Reactants is EQUAL to the Mass
of the Products
Law of Conservation of Matter
[Mass]
© KeslerScience.com
Quick Action – Elements and Compounds
1. Complete the chart by
counting the elements and
naming them.
2. Record your answers in the
chart located in your notes.
Formula
H2O
NaCl
C6H12O6
NaOH
# of different
elements
Name of
elements
© KeslerScience.com
Quick Action – Complete & Turn it in!
1. Cut out the INB template
and glue along the narrow
tab.
2. Looking at the formula,
decide if it is a compound
or an element.
3. Name each element in the
formula.
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