Download The Periodic Table of Elements and Atoms…

Atoms
&
The Periodic Table of Elements
History first…
Alchemy
Robert Boyle
John Dalton
Dmitri Mendeleev
Jons Berzelius
Alchemy:
one of the earliest forms of
chemistry.
Scientists try (unsuccessfully) to turn
metals of low value (iron or lead) into
gold.
Though they were unsuccessful, they
contributed knowledge to the chemical
world. For example how changes affect
matter.
Today, Chemistry is the study of
matter, including its properties,
composition, and the changes it
undergoes.
It’s About Matter!
• MatterAnything that
takes up space
and has mass.
(ex., Pizza and
Air)
Robert Boyle…
Considered the first real
chemist. He introduced the first
definition of an element as a
pure substance that cannot be
broken into simpler substances
by chemical means.
John Dalton…
introduced the idea that each
element was made up of
a
different kind of atom.
Atomic Structure…
An atom is made up of three basic parts:
protons, neutrons, and electrons. The
protons which have a positive charge [+]
and the neutrons which have no charge,
form the nucleus in the center of the atom.
The electrons which have a negative
charge [-], move sporadically around the
nucleus.
Draw this model on your paper
•Electrons are negatively charged particles that
have a very low mass. There are an equal
number of electrons as there are protons.
•Protons are positively charged particles found
in the nucleus. There are an equal number of
protons as there are electrons.
•Neutrons, also found in the nucleus, have no
electrical charge. They are neutral. They have
about the same mass as a proton.
•The nucleus is the central core of an atom
that contains most of the mass of an atom
because it contains both the neutrons and
protons.
Each atom has an equal number
of protons and electrons.
Because the negative charge of
the electrons balances the
positive charge of the protons,
atoms are neutral.
Jons Berzelius…
introduced a system of abbreviation
for the elements, which is still in use
today. The symbol was determined
by using the first letter of the
element’s name or Latin name and
capitalizing it and in most cases
added another letter, which remained
lower case.
The atomic symbol is where you capitalize
the first letter and if there are any other
letters in the symbol they are lower case.
Examples: H for Hydrogen
O for Oxygen
Ca for Calcium
Au for Gold
Chemical formulas show what
elements and how many
atoms of that element have
combined to make a
compound/chemical!
Can you tell what elements it took to make the
following chemicals/compounds?
•
•
•
•
•
•
Water: H2O
Carbon Dioxide: CO2
Baking Soda: NaHCO3
Sugar: C12H22O11
Ammonia: NH3
Rubbing alcohol: C3H7OH
•
•
•
•
•
•
Hydrochloric Acid: HCl
Sodium Chloride: NaCl
Cream of Tartar: KHC4H4O6
Battery Acid: H2SO4
Starch: C6H10O5
Aspirin: C9H8O4
Atom vs. Molecules
• Element is a pure substance that cannot be
broken down any further. It is in its
simplest form! Each element is represented
by an atom.
• Molecules are particles made up of two or
more atoms bonded together that make up
substances.
Compound vs. Mixture
• Compound is a substance that is made up
of two or more elements chemically
bonded together.
• Mixture is a substance that is made up of
two or more elements, but the elements are
not chemically bonded together.
Two types of mixtures!!!
• Homogeneous and Heterogeneous
Let’s use the prefixes to help us remember
which one is which!!!
• Remember, Prefixes bring with them a
meaning to whatever we attach them to
Homo vs. Hetero
• Homo means same
• Hetero means different
• Homogeneous- a mixture in which
substances are evenly distributed
throughout the mixture. It all looks the
same!!! Example, Milkshake
• Heterogeneous Mixture- a mixture in
which substances are unevenly distributed
throughout the mixture. You can see the
different parts!!!
• Example, Fruit Salad
Dmitri Mendeleev…
arranged the elements into a systematic
chart or table called the Periodic Table
of Elements. Today’s periodic table of
elements based on Mendeleev’s version
groups the elements by similar
properties. It gives the symbol, the
atomic number, and the atomic mass of
each element.
An example of how an atom is represented on the
Periodic Table of Elements.
1
H
Atomic Number-tells you the
amount of protons and electrons.
Atomic Symbol
Hydrogen
1.0079
Full Name
Atomic Mass
How do you know how many protons,
electrons, and neutrons each atom has?
• The atomic # tells you how many protons and
electrons there are in each atom.
• You need a formula to calculate the amount of
neutrons. The formula is:
Atomic mass(large #)
minus the Atomic #(smaller #)
equals the amount of neutrons.
or
AM – A# = neutrons
Practice finding the amount of Protons, Electrons,
and Neutrons:
1. Aluminum
2. Oxygen
Practice continued
3. Mercury
4. Hydrogen
The Periodic Table of Elements
Each box on the table represent an atom. Start
seeing each element as a different atom.
The atoms are arranged periodically based on
their properties/characteristics.
It works out that the atoms are in order of
increasing atomic number (protons/electrons) as
you move from left to right.
The boxes are arranged into a grid of periods
(Horizontal rows) and groups (Vertical
columns)
Two different
numbering systems!
• One of the numbering systems:
– Numbers the groups(columns) 1-18!
• The other numbering system:
– Divides the table of elements into two categories:
• Main Group Elements- the first two
groups(columns) and last six groups(columns). We
notate the group number with the letter “A”. (Ex.,
2A)
• Transition Metals-the ten groups(columns) in the
center. We notate the groups number with the letter
“B”. (Ex., 3B)
•
List the numbers as they would appear at the top of
each column on the P.T.o.E.:
1_ 2_
___ ___ ___ ___ ___ __
___ ___ ___ ___ ___ ___ ___ ___ ___ ___
_1a_ 2a_
___ ___ ___ ___ ___ __
___ ___ ___ ___ ___ ___ ___ ___ ___ ___
Using Period #’s and Group #’s as coordinates to locate
elements/atoms:
1.
2.
3.
4.
P2 G17:
P4 G4a:
P3 G6a:
P6 G12:
Groups are sometimes called
families!
• Alkali metals (Group 1)-highly reactive & do
not occur freely in nature.
• Alkaline Metals (Group 2)-highly reactive &
found on earth.
• Rare Earth Elements(Inner transition metals)synthetic(man-made)
• Hologens (Group 17)-non-metals that require
only one more valence electron to be stable.
• Noble Gases (Group 18)-they do not combine
easily if at all with other atoms/elements.
Let’s talk organization!
The elements are divided into 3
categories: Metals, Metalloids, and
Nonmetals. We use the “Zig-Zag” line as
a reference.
The metals are to the left of the “Zig-Zag”
line except: Hydrogen-it’s a nonmetal
The metalloids are on the “Zig-Zag” line.
except: Aluminum, it’s all metal!
The nonmetals are to the right of the
“Zig-Zag line. except: Hydrogen-even
though it is located to the left it is still a
nonmetal
Memorizing the states of each atom at room
temperature helps use the periodic table as a tool!
• There are 11 gases and 2 liquids at room
temperature:
Gases
hydrogen-
Neon
Liquids
Bromine
Helium-
Xenon
Mercury
Nitrogen
Argon
Oxygen
Krypton
Fluorine
Radon
Chlorine
Holding Atoms in a Compound
Together!
• Each atom has energy levels/orbitals that
can only hold a certain amount of electrons.
Electrons in orbitals farthest away from the
nucleus have higher amounts of energy than
those found in orbitals closer to the nucleus.
• The electrons in the most outer energy
level/orbital have the most energy and are called
valence electrons.
• The valence electrons are the electrons involved
in forming chemical bonds.
• Chemical bonds are the attraction between atoms
in a compound.
How many Electrons are located in the most
outer energy level?
These are the valence electrons which
are used to bond with!! 
How do you know how many Valence
Electrons each atom has?
• It’s easy…..just look at the periodic table!!
• The group # tells you the number of
valence electrons:
– Group 1(1a)= 1 valence electron
– Group 2(2a)= 2 valence electrons
– Group 13(3a)= 3 valence electrons
– Group 14(4a)= 4 valence electrons
Helium, which only has 2 valence electrons, is
the exception in group 18(8a).
• Noble Gases have 8 valence electrons, which
makes them the most stable!
 Remember: Helium only needs 2 to be considered
stable!
• The octet rule: an atom will form a chemical
bond with another atom if the bonding will cause
both atoms to have 8 valence electrons.
 Remember: Hydrogen & Helium only need 2 to be
considered stable!
Dot Structures: a tool used to help illustrate how
atoms conform to the octet rule in a compound.
Plus, they’re fun to make
Ionic Bonding
occurs when a metal transfers one or more
electrons to a nonmetal in an effort to attain
a stable octet of electrons.
 One of the ions will be a positively
charged ion and the other will be a
negatively charged ion.
– Example: Cs + At =
–
– Example: Na + S =
–
– Example: Ga + Br =
•Covalent Bonding- occurs when two
or more nonmetals share electrons,
attempting to attain a stable octet of
electrons at least part of the time.
• Example: C + O =
• Example: H + O =
• Example: H + H =
Polyatomic Ionic Bonding
• A combination of more than one nonmetal
atoms with at least one metal atom. This is
three or more elements!
It is a Polyatomic Ionic Bond if…
There are 3 or more elements and at
least one of the elements is a
metal!!!!!
Identify the following as
Ionic, Covalent, or a Polyatomic ionic bond:
1.
2.
3.
4.
5.
6.
CaCl2
CO2
H2O
BaSO4
K2O
NaF
7. Na2CO3
8. CH4
9. SO3
10.LiBr
11.MgO
12.NH4Cl
Things to remember:
That chemistry is study of
matter, including its properties,
composition, and the changes it
undergoes.
That matter is anything that has
mass and volume (takes up
space)
What is a Property?
• A property is a quality specific
to a substance that helps us to
classify or identify the
substance.
It is a description of matter! 
What is the difference between
a Property and a Change?
A property is the
description/characteristic of matter
and/or ability to change.
A Change is the actual change or
reaction that occurs.
Physical Property/Change
• Physical Property- a characteristic
of matter that can be observed
and sometimes changed without
producing a new kind of matter.
Color, size, texture, and shape are
examples of physical properties.
More Examples of
Physical Properties
• Density- how tightly packed matter is in a
given amount of space (D= m/v)
• Malleability- the ability to be hammered
into a shape.
• Viscosity- a fluids resistance to flow.
• Ductility- the ability to be pulled into thin
wires.
• Solubility-the ability to dissolve.
Chemical Property
• A chemical property is a description of how a
certain kind of matter reacts.
• When matter reacts one of two things happen:
The matter combines with another form of
matter to produce a new kind of matter?
Or
Does the matter break apart to produce a
new kind of matter?
Which one would be decomposition and which one
would be composition?
Composition Reaction
A composition reaction involves
combining two forms of matter to
produce a new kind of matter.
For example, when sodium is combined
with chloride…salt is formed.
An Example of a
Composition Reaction:
The iron metal of nails
combined with oxygen
forms a reddish-brownish
solid called rust. Rust is a
new kind of matter with its
own set of physical and
chemical properties.
Decomposition
A Decomposition reaction involves
combining one type of matter with
something else (matter or energy).
The matter breaks down and forms a
new kind of matter.
Think about
wood burning.
There are four basic
Chemical Properties/Changes:
The ability to react with acid
The ability to react with oxygen(burning and
rusting)
The ability to react with electricity
The ability to react with another substance
Example of a
Chemical Property/Change
• When Oxygen( a kind of
matter) combines with
aluminum (also a kind of
matter) it has the ability to
form a coating. This coating is
a new kind of matter with
different physical and chemical
properties.
Copy the following and write down
whether it is
physical or chemical
next to it:
Physical or Chemical?
•
•
•
•
•
•
•
•
DuctilityFlammabilityReacts with Acid to form H2OSolubilitySour TasteViscosityOdorReacts with water to form a gas-
Phases of Matter
The phases of Matter are a physical
property of matter.
Think about water for example.
There are four different
phases of matter:
Plasma
Solid
Liquid
Gas
Plasma
Plasma is a phase of matter that
is similar to a gas. Unlike gas,
Plasma is produced by burning
gases at very high temperatures,
as in the sun and other stars. It
may also be produced if the
matter is exposed to a significant
electrical current.
Solid
• A solid has definite shape
and definite volume.
Under regular
circumstances, the shape
and volume of solids do
not change.
• Molecules vibrate in place
Liquid
• A liquid has a definite
volume, but not a definite
shape. Liquids take the
shape of the container they
are in, but the volume
remains the same.
• Molecules have a rapid, random
motion.
Gas
• A Gas does not have a
definite shape or a definite
volume. Like liquids the
gas takes the shape of its
container. (Remember the
balloon and air?) Unlike
Liquids the volume does not
necessarily stay the same.
• Molecules have very rapid,
random motion.
There are several words that indicate a possible change
in phase and all would result in physical changes. Use
the following list as key words for physical properties
and changes!!!
•
•
•
•
•
•
•
*melting*freezing*evaporating*sublimation*boiling*vaporization*condensation-
Two Types of Solids:
A Crystalline solidthe molecules are
arranged in a fixed,
regular pattern
Solids that have such a
repeating pattern are
called crystals.
An Amorphous
Solid- the molecules are
not arranged in a fixed
regular pattern; they are
arranged in a random
pattern.
Solids that have a
random pattern are called
amorphous.
Physical vs. Chemical
The following are key words that represent either
physical or chemical changes. The letter “p”
identifies a physical change key word and the
letter “c” identifies a chemical change key word:
1. cuts2. boils3. burns4. corrodes5. smash6. rusts-
7. evaporates8. reacts9. hammering10. viscosity11. spoiling12. folds13. decomposes14. paint15. mixing16. combining-
17. dissolve18. luster19. bleach20. density21- bonds with22. malleability23. ductility24. mixture25. compound-
Are we finished?
You bet we are!!!!!