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The highlights are:
1. Elements
2. Periodic Table
3. Atomic number
4. Atomic mass and Isotopes
5. Valence Electrons
6. Properties of Metals, Non-Metals, and Metalloids
1.
Periodic Table of Elements
3.
chlorin
e nitrog
en
silver
gold
mercury
oxyge hydrogen
n
niobium
sodium
neodymium
carbon
4.
Science has come
along way since
Aristotle’s theory of
Air, Water, Fire, and
Earth.
Scientists have
identified 90 naturally
occurring elements,
and created about 28
others.
5.
The elements,
alone or in
combinations,
make up our
bodies, our world,
our sun, and in
fact, the entire
universe.
6.
The most abundant element in the
earth’s crust is oxygen.
7.
Periodic Table
The periodic table organizes the elements in a
particular way. A great deal of information about an
element can be gathered from its position in the
period table.
For example, you can predict with reasonably good
accuracy the physical and chemical properties of
the element. You can also predict what other
elements a particular element will react with
chemically.
Understanding the organization and plan of the
periodic table will help you obtain basic information
about each of the 118 known elements.
8.
Key to the Periodic Table
Elements are organized on
the table according to their
atomic number, usually found
near the top of the square.
The atomic number refers
to how many protons an
atom of that element has.
For instance, hydrogen
has 1 proton, so it’s
atomic number is 1.
The atomic number is
unique to that element.
No two elements have
the same atomic number.
9.
What’s in a square?
Different periodic
tables can include
various bits of
information, but
usually:
atomic number
symbol
atomic mass
number of valence
electrons
state of matter at room
temperature.
10.
Atomic Number
This refers to how
many protons an
atom of that
element has.
No two elements,
have the same
number of protons.
Bohr Model of Hydrogen Atom
Wave Model
11.
Atomic Mass
Atomic Mass refers
to the “weight” of
the atom.
It is derived at by
adding the number
of protons with the
number of This is a helium atom. Its
Hatomic mass is 4 (protons
neutrons. plus neutrons).
What is its atomic number?
12.
View CD-ROM Atoms and Elements
13.
Atomic Mass and Isotopes
While most atoms have
the same number of
protons and neutrons,
some don’t.
Some atoms have more
or less neutrons than
protons. These are called
isotopes.
An atomic mass number
with a decimal is the total
of the number of protons
plus the average number
of neutrons.
14.
Atomic Mass Unit (AMU)
The unit of
measurement for
an atom is an AMU.
It stands for atomic
mass unit.
One AMU is equal
to the mass of one
proton.
15.
Atomic Mass Unit (AMU)
There are
6 X 1023 or
600,000,000,000,000,
000,000,000 amus in
one gram.
(Remember that
electrons are 2000
times smaller than one
amu).
16.
All elements have
C Carbon
their own unique
symbol.
It can consist of a
single capital letter,
or a capital letter
and one or two
lower case letters.
Copper
18.
Valence Electrons
The number of valence
electrons an atom has
may also appear in a
square.
Valence electrons are the
electrons in the outer
energy level of an atom.
These are the electrons
that are transferred or
shared when atoms bond
together.
20.
Properties of Metals
Metals are good conductors
of heat and electricity.
Metals are shiny.
Metals are ductile (can be
stretched into thin wires).
Metals are malleable (can
be pounded into thin
sheets).
A chemical property of
metal is its reaction with
water which results in
corrosion.
21.
Properties of Non-Metals
Non-metals are poor
conductors of heat and
electricity.
Non-metals are not
ductile or malleable.
Solid non-metals are
brittle and break
easily.
They are dull.
Many non-metals are
gases.
Sulfur
22.
Properties of Metalloids
Metalloids (metal-like)
have properties of both
metals and non-metals.
They are solids that can
be shiny or dull.
They conduct heat and
electricity better than non-
metals but not as well as
metals.
They are ductile and
malleable.
Silicon
25.
Families Periods
Columns of elements are called Each horizontal row of
groups or families. elements is called a period.
Elements in each family have The elements in a period
similar but not identical are not alike in properties.
properties.
In fact, the properties
For example, lithium (Li),
change greatly across
sodium (Na), potassium (K),
and other members of family IA
even given row.
are all soft, white, shiny metals. The first element in a
All elements in a family have period is always an
the same number of valence extremely active solid. The
electrons. last element in a period, is
always an inactive gas.
38.
The hydrogen square sits atop Family
AI, but it is not a member of that family.
Hydrogen is in a class of its own.
It’s a gas at room temperature.
It has one proton and one electron in its
one and only energy level.
Hydrogen only needs 2 electrons to fill
up its valence shell.
39.
Alkali Metals
The alkali family is found in
the first column of the
periodic table.
Atoms of the alkali metals
have a single electron in
their outermost level, in
other words, 1 valence
electron.
They are shiny, have the
consistency of clay, and are
easily cut with a knife.
40.
Alkali Metals
They are the most
reactive metals.
They react violently
with water.
Alkali metals are
never found as free
elements in nature.
They are always
bonded with
another element.
41.
What does it mean to be
We will be describing elements according to their
reactivity.
Elements that are reactive bond easily with other
elements to make compounds.
Some elements are only found in nature bonded with
other elements.
What makes an element reactive?
An incomplete valence electron level.
All atoms (except hydrogen) want to have 8 electrons in their
very outermost energy level (This is called the rule of octet.)
Atoms bond until this level is complete. Atoms with few
valence electrons lose them during bonding. Atoms with 6, 7,
or 8 valence electrons gain electrons during bonding.
45.
Alkaline Earth Metals
They are never found uncombined in nature.
They have two valence electrons.
Alkaline earth metals include magnesium
and calcium, among others.
46.
Transition Metals
Transition Elements
include those elements
in the B families.
These are the metals
you are probably most
familiar: copper, tin,
zinc, iron, nickel, gold,
and silver.
They are good
conductors of heat and
electricity.
47.
Transition Metals
The compounds of transition metals are usually
brightly colored and are often used to color paints.
Transition elements have 1 or 2 valence electrons,
which they lose when they form bonds with other
atoms. Some transition elements can lose electrons
in their next-to-outermost level.
48.
Transition Elements
Transition elements have properties
similar to one another and to other
metals, but their properties do not fit in
with those of any other family.
Many transition metals combine
chemically with oxygen to form
compounds called oxides.
49.
Boron Family
The Boron Family is
named after the first
element in the family.
Atoms in this family have 3
valence electrons.
This family includes a
metalloid (boron), and the
rest are metals.
This family includes the
most abundant metal in the
earth’s crust (aluminum).
50.
Carbon Family
Atoms of this family have 4
valence electrons.
This family includes a non-
metal (carbon), metalloids, and
metals.
The element carbon is called
the “basis of life.” There is an
entire branch of chemistry
devoted to carbon compounds
called organic chemistry.
51.
Nitrogen Family
The nitrogen family is named
after the element that makes
up 78% of our atmosphere.
This family includes non-
metals, metalloids, and metals.
Atoms in the nitrogen family
have 5 valence electrons.
They tend to share electrons
when they bond.
Other elements in this family
are phosphorus, arsenic,
antimony, and bismuth.
52.
Oxygen Family
Atoms of this family have 6
valence electrons.
Most elements in this family
share electrons when
forming compounds.
Oxygen is the most
abundant element in the
earth’s crust. It is extremely
active and combines with
almost all elements.
53.
Halogen Family
The elements in this family are
fluorine, chlorine, bromine,
iodine, and astatine.
Halogens have 7 valence
electrons, which explains why
they are the most active non-
metals. They are never found
free in nature.
Halogen atoms only need
to gain 1 electron to fill their
outermost energy level.
They react with alkali
metals to form salts.
54.
Noble Gases
Noble Gases are colorless gases that are extremely un-reactive.
One important property of the noble gases is their inactivity. They are
inactive because their outermost energy level is full.
Because they do not readily combine with other elements to form
compounds, the noble gases are called inert.
The family of noble gases includes helium, neon, argon, krypton, xenon,
and radon.
All the noble gases are found in small amounts in the earth's atmosphere.
55.
Rare Earth Elements
The thirty rare earth
elements are composed
of the lanthanide and
actinide series.
One element of the
lanthanide series and
most of the elements in
the actinide series are
called trans-uranium,
which means synthetic or
man-made.
56.
Mendeleev
In 1869, Dmitri Ivanovitch
Mendeléev created the first accepted
version of the periodic table.
He grouped elements according to
their atomic mass, and as he did, he
found that the families had similar
chemical properties.
Blank spaces were left open to add
the new elements he predicted
would occur.
57.
All matter is composed of atoms and groups
of atoms bonded together, called molecules.
Substances that are made from one type of
atom only are called pure substances.
Substances that are made from more than one
type of atom bonded together are called
compounds.
Compounds that are combined physically, but
not chemically, are called mixtures.
58.
Elements, Compounds,
Mixtures
Sodium is an element.
Chlorine is an
element.
When sodium and
chlorine bond they
make the compound
sodium chloride,
Compounds have different properties
commonly known as than the elements that make them up.
table salt.
Table salt has different properties than
sodium, an explosive metal, and chlorine,
a poisonous gas.
59.
Elements, Compounds,
Mixtures
Hydrogen is an element.
Oxygen is an element.
When hydrogen and
oxygen bond they make
the compound water.
When salt and water are
combined, a mixture is
created. Compounds in
mixtures retain their
individual properties.
The ocean
is a
60.
Elements, compounds, and
Mixtures can be separated by physical
means.
Compounds can only be separated by
chemical means.
Elements are pure substances. When the
subatomic particles of an element are
separated from its atom, it no longer retains
the properties of that element.
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