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Unit 1
Physical Science
Atoms and Elements
Nature of Science
"is the search for the truth“

First Nations perspectives
• Medicine Wheel
• Four directions
• Four Elements
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Early Civilization perspectives
• Greek Elements
• Chemistry started with Democritus
Classifying Matter
• Matter has ‘property’
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Pure Substances
• Elements
• Compounds
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Mixtures
• Mechanical mixture
• Suspension
• Solution
Using mixtures in mining
Physical Properties
• Water is unique
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Physical Properties
•
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Colour and lustre
Melting point
Boiling point
Density
Solubility
Ductility
Crystal Shape
Conductivity
Hardness
Texture
Malleability
Chemistry
is the study of the composition and
properties of matter
Chemists interested in:
1) composition and structure of
substances
2) the properties of these substances
3) the conditions under which these
substances change to form new ones

Forms of Matter
• Mass
• Volume
• Four States: Solid, Liquid, Gas, Plasma
Chemical Properties
• Change and Reaction
• Takes heat energy or light

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Combustion
Controlled Change
• Traditional uses – preserving foods
• Medicines – herbs and plants
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Polyethylene Plastics
Models of Matter
Remember: began with the Greeks
- Democritus
Then: Alchemists
Finally: Modern Chemistry Begins
Models of the Atom
Different Ways of Understanding
1) Greeks (Democritus) – 400 B.C.
2) Dalton – 1803
A small particle with several
smaller pieces within.
3) Thompson – 1898
The Plum Pudding Model
4) Rutherford – 1911
Concentric Rings
5) Bohr – 1923
6) Scroedinger – Present
Quantum Mechanical Model
Based on the probability of where
electrons would be found about the
nucleus.
Subatomic Particles
We are interested in three particles and
their mass, charge, and location.
Mass
Charge
Location
Proton
1 AMU
+
In Nucleus
Neutron
1 AMU
Neutral
In Nucleus
Electron
1/1836
AMU
-
Outside
Nucleus
AMU – Atomic Mass Unit
Elements and Compounds

Properties of Metals
• Low melting points mean low strength
• Creating alloys


Properties of Non-metals
• Do not conduct electricity
• Could be solid, liquid, or gas
Properties of Metalloids
• Both metallic and non-metallic properties
• Are semi-conductors of electricity

Element Symbols
• Short way of representing
• Represents 1 atom in a chemical formula
• Many based on the Latin name

Some Common Elements
• Iron
• Carbon
• Hydrogen
• Oxygen
• Sodium
• Chlorine
Compounds
 are a combination of two or more
elements
Ionic Compounds
 when an atom loses an electron, it
becomes positive which is known as a
cation.
 when an atom gains an electron, it
becomes negative which is known as
an anion.
 Cations and anions are attracted to
each other and thus come together to
form a compound.
• Potassium is losing an electron and
becomes positively charged.
• Chloride is gaining an electron and
becomes negatively charged.
• K and Cl now attract each other.
•The compound has a neutral charge.
Molecular Compounds
 Are pure substances from non-metal
elements.

Form covalent bonds
• shared electrons
The two Hydrogen
atoms share their
outer electrons with
the Oxygen atom to
form H20.
Chemical Formulas and Names
H
+
H
+
O

H2O
Hydrogen (2 atoms) and oxygen (1 atom)
Combine to form Water (1 molecule)


In an atom/element the number
of protons is always equal to the
number of electrons.
We always round the atomic
mass to the nearest whole
number.
# Neutrons = Atomic Mass - Atomic Number
16
S
Atomic Number – Tells
us the number of
protons
Element Symbol
Sulfur
Element Name
32.06
Atomic Mass – tells us
the number of neutrons
and protons
Ions
 ions are formed when an
electron is either gained or lost.
 when an electron is gained, it
becomes a negative ion and we
call this an anion.
 when an electron is lost, it
becomes a positive ion and we
call this a cation.
When naming a cation, simply add the
word 'ion' to the end of the element
name.
Ex//
Mg - Magnesium  Mg+2 - Magnesium ion
Ca - Calcium  Ca+2 - Calcium ion
Na - Sodium  Na+1 - Sodium ion
When naming an anion, drop the last few
letters of the element name and add the
ending -ide.
Ex//
O - Oxygen  O-2 – Oxide
N – Nitrogen  N-3 - Nitride
Cl - Chlorine  Cl-1 – Chloride

ions become charged because they want 8
electrons in their outer shell (octet)
When an anion and a cation come
together, they form a compound.
NAMING
 the cation always goes first, followed by the
anion.
 use the element name for the cation.
 use the ion name for the anion.
1.
a)
b)
c)
d)
e)
f)
g)
h)
i)
Li+1
Mg+2
Ca+2
Cu+2
Cr+3
Fe+2
Ag+1
Al+3
Fe+3
P-3
F-1
N-3
O-2
S-2
S-2
S-2
Br-1
O-2
Cl-1
K+1
Ca+2
Cr+3
O-2
N-3
KCl
K2O
K3N
Potassium Potassium Potassium
Chloride
Oxide
Nitride
CaCl2
CaO
Ca3N2
Calcium
Calcium
Calcium
Chloride
Oxide
Nitride
CrCl3
Cr2O3
CrN
Chromium Chromium Chromium
(III)
(III)
(III)
Chloride
Oxide
Nitride
2. Write the chemical formula for each
of the following compounds.
a)
b)
c)
d)
e)
f)
g)
h)
Potassium chloride
Calcium nitride
Copper (II) oxide
Iron (III) bromide
Magnesium phosphide
Aluminum selenide
Chromium (III) sulfide
Tin (II) oxide
3. Name each of the following compounds.
a) Li2O
b) Ag3N
c) SnO2
d) CrCl3
e) BaS
f) Fe2O3
g) Cu3P
h) V2O5
G. Writing Equations
Products
- are the chemicals that are made or
produced in a chemical reaction
Reactants
- are the chemicals that begin or go
into the reaction before it takes place
Chemical Reaction
- when the chemicals that go into the
reaction change and new products
(chemicals) are formed.
Ex.
MgI2 +
Na2O 
Reactants
NaI
+
MgO
Products
When we write the compounds, we must
make sure that they are balanced.
‘+’ – tells us that two compounds are
combining.
Key Words – combines, mixes,
reacts, and, etc.
‘’ – acts as an equals sign to
separate reactants and products.
Key Words – to form, to produce,
to make, synthesize, decompose,
break down, etc.
Sample Problems
1) Magnesium bromide reacts with
calcium nitride to form magnesium
nitride and calcium bromide.
2) Copper (II) oxide reacts with
lithium phosphide and produces
copper (II) phosphide and lithium
oxide.
3) Tin (IV) sulfide reacts with calcium iodide
and makes tin (IV) iodide and calcium
sulfide.
4) Lithium chloride decomposed to form
lithium and chlorine.
Magic Seven – if ever the following elements are by
themselves, they are found in pairs (diatomic).
N2, O2, F2, Cl2, Br2, I2, At2, H2
5) Calcium reacts with iodine to form
calcium iodide.
6) Chromium (III) iodide combines
with sodium phosphide to make
chromium (III) phosphide and
sodium iodide.
H. Writing Word Equations
Examples
1) CaI2 +
Al2O3

CaO
+ AlI3
2) CrI2 +
3) Fe2O3
+
Cu2S

CrS
KF

FeF3
+
+
CuI
K2O
I. Acids and Bases
Acids
 Have a sour taste
 Very corrosive
 Neutralize bases
 Conduct electricity very well
 Dissolve in water to produce hydrogen
ions (H+) in solution
 When an acid and a base neutralize each
other, they form salt and water
NaOH
Sodium
Hydroxide
+
HCl

Hydrochloric
Acid
H2O
Water
+
NaCl
Salt
Bases
 Have a bitter taste
 Very corrosive
 Neutralize acids
 Conduct electricity very well
 Dissolve in water to produce hydroxide
ions (OH-) in solution
 When an acid and a base neutralize each
other, they form salt and water
Acid-Base Indicators
• Acid – Base indicators are substances that
change different colors when added to acids
and bases.
• Litmus Paper
– red in an acid
- blue in a base
• Bromothymol Blue – yellow in an acid
- blue in a base
pH paper – is another type of indicator
that can change to several different
colours to tell the scientist how acidic
or basic the solution is.
pH Scale
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An acid-base indicator will not tell you how
acidic or basic a solution is.
The pH scale indicates the level of acidity
of a solution and it ranges from 0-14.
pH of 0-6.9 is acidic.
pH of 7 is neutral.
pH of 7.1-14 is basic.
The pH scale is logarithmic (based on the
power of ten). This means the difference
between a pH of 5 and 6 is actually ten
times. The difference between 4 and 6 is
actually 100 times.
Maintaining a constant pH is often very
important for biological systems.
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Human blood has a pH range of 7.357.45. Any change from this could be fatal.
Plants grow best in soil with a pH between
6 and 7. Any higher or lower, prevents
the plants from absorbing nutrients.
Shampoo normally has a pH of about 8.
The human scalp has a pH of about 6. A
scalp that becomes too basic results in
dandruff.
THE END
Exam Time!