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Color code the periodic table
according to these guidelines:
• Metals -- OUTLINE whole section (NOT
every individual box) in orange
• Nonmetals -- OUTLINE whole section in
dark blue
• Metalloids -- OUTLINE whole section in
dark green
The Periodic Table
Metals
Nonmetals
Metalloids
• Alkali metals -- FILL IN section in red (do
NOT obscure the outline color that already
exists)
• Alkaline earth metals -- FILL IN section in
yellow
• Halogens -- FILL IN section in light green
• Noble gases -- FILL IN section in light
blue
Alkali Metals
Alkaline Earth Metals
Halogens
Noble Gases
• Transition metals -- FILL IN entire section
in orange
• Inner Transition metals -- FILL IN entire
section in pink
• Radioactive Elements – Place a black dot
in the upper right corner of every
radioactive element
• Include a legend on your periodic table
explaining what each color represents.
Transition Metals
Inner Transition Metals
Radioactive Elements
gold silver
heliumoxygen
mercury
hydrogen
sodium
nitrogen
niobium
neodymium
chlorine
carbon
Elements
Science has come a
long way since
Aristotle’s theory of
Air, Water, Fire, and
Earth.
Scientists have
identified 90 naturally
occurring elements,
and created about 28
others.
Elements
The elements,
alone or in
combinations,
make up our
bodies, our world,
our sun, and in
fact, the entire
universe.
The most abundant element in the
earth’s crust is oxygen.
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.
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.
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.
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
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
neutrons. HThis is a helium atom. Its atomic mass is 4 (protons plus neutrons).
What is its atomic number?
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.
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.
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).
Symbols
All elements have
their own unique
symbol.
It can consist of a
single capital letter,
or a capital letter
and one or two
lower case letters.
CCarbon
CuCopper
Common Elements and
Symbols
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.
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.
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
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
Families Periods Columns of elements are
called groups or families.
Elements in each family
have similar but not
identical properties.
For example, lithium (Li),
sodium (Na), potassium
(K), and other members of
family 1 are all soft, white,
shiny metals.
All elements in a family
have the same number of
valence electrons.
Each horizontal row of elements is called a period.
The elements in a period are not alike in properties.
In fact, the properties change greatly across even given row.
The first element in a period is always an extremely active solid. The last element in a period, is always an inactive gas.
Hydrogen
The hydrogen square sits atop Family 1,
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.
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.
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.
Alkaline Earth Metals
They are never found uncombined in nature.
They have two valence electrons.
Alkaline earth metals include magnesium
and calcium, among others.
Transition Metals
Transition Elements include those elements in the 3-12 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.
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.
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.
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.
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.
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.
What does it mean to be
reactive?
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.
5
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.
Matter
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.
Bell ringer
• Name a scientist that you remember and
tell for what he/she is known, did, or
discovered. Give any other information
you can such as branch of science, prizes
won, country of origin, etc.
Atomic Structure
Defining the Atom
What is an Atom?
The smallest part of an element that retains its identity in a
chemical reaction.
Atomic History
• https://www.youtube.com/watch?v=thnDxF
dkzZs
HISTORY OF THE ATOM
460 BC Democritus develops the idea of atoms
he pounded up materials in his pestle and
mortar until he had reduced them to smaller
and smaller particles which could not be
divided and called these:
ATOMA
(greek for indivisible)
Historic Models of the Atom
• Aristotle (384-322 BC) didn’t think there
was a limit to the number of times matter
could be divided.
• He knew there were small particles. Air,
Fire, Earth, Water
HISTORY OF THE ATOM
1808 John Dalton
suggested that all matter was made up of
tiny spheres that were able to bounce around
with perfect elasticity and called them
ATOMS
Dalton’s Atomic Theory
1. All elements are composed of atoms (which
can’t be divided).
2. Atoms of the same element have the same
mass and atoms of different elements have
different masses.
3. Compounds contain atoms of more than one
element.
4. In a compound, atoms of different elements
always combine in the same way.
Dalton’s atom
Dalton’s Atomic Theory
Most of Dalton’s statements are now known to be flawed.
As we continue to study the atom, we will talk about discoveries that disproved Dalton’s statements.
Scientists have revised the theory due to new discoveries!
HISTORY OF THE ATOM
1898 Joseph John Thomson
found that atoms could sometimes eject a far
smaller negative particle which he called an
ELECTRON
J.J. Thomson, 1897• Discovered the electron, the subatomic particle
with a negative charge
• His experiments involved the use of a cathode
ray tube
Animation of
Thomson’s model
HISTORY OF THE ATOM
Thomson develops the idea that an atom was made up of
electrons scattered unevenly within an elastic sphere surrounded
by a soup of positive charge to balance the electron's charge
1904
like plums surrounded by pudding.
PLUM PUDDING
MODEL
Thomson’s Atomic Model
• Developed the Plum
Pudding model.
(think of a chocolate
chip cookie)
• Electrons evenly
distributed throughout
a positively charged
material.
Plum Pudding Model
e- e-
e-
e-
e-
Sphere of
Positive charge
HISTORY OF THE ATOM
1910 Ernest Rutherford
oversaw Geiger and Marsden carrying out his
famous experiment.
they fired Helium nuclei at a piece of gold foil
which was only a few atoms thick.
they found that although most of them
passed through. About 1 in 10,000 hit
something
HISTORY OF THE ATOM
gold foil
helium nuclei
They found that while most of the helium nuclei passed
through the foil, a small number were deflected and, to their
surprise, some helium nuclei bounced straight back.
helium nuclei
Ernest Rutherford, 1911
• Tested theory that electrons were evenly
distributed throughout the atom within
positively charged material
• Performed the Gold-Foil Experiment
Ernest Rutherford
• If Thomson’s model was correct, most of
the alpha particles should pass through
with a little deflection
Rutherford’s Model
• Proposed that atoms contain a nucleus, a
small, dense, positively-charged sphere in
the center of the atom.
• Atom contains mostly empty space.
• The nucleus is tiny compared with the
atom as a whole.
Ernest Rutherford
Thomson’s model Rutherford’s model
Rutherford’s model:
Nuclear Atom
e- e-
e-
+
+ +
Rutherford did
NOT know about
neutrons!
HISTORY OF THE ATOM
Rutherford’s new evidence allowed him to propose a more
detailed model with a central nucleus.
He suggested that the positive charge was all in a central
nucleus. With this holding the electrons in place by electrical
attraction
However, this was not the end of the story.
• The Houston
Astrodome occupies
more than nine acres
and seats 60,000
people.
• If the stadium were a
model for an atom, a
marble could
represent its nucleus!
HISTORY OF THE ATOM
1913 Niels Bohr
studied under Rutherford at the Victoria
University in Manchester.
Bohr refined Rutherford's idea by adding
that the electrons were in orbits. Rather
like planets orbiting the sun. With each
orbit only able to contain a set number of
electrons.
Bohr’s Atom
electrons in orbits
nucleus
Summary
• Dalton’s Theory- all matter is made up of
atoms, which can’t be divided
• Thomson’s Model- discovered atoms were
made up of smaller particles (these
smaller particles are charged)
• Rutherford’s Theory- discovered the
positively charged nucleus
Development of Atomic Theory Timeline
Purpose:
To make an atomic theory flow map highlighting and discussing the main theories
and/or discoveries for the following people or ideas:
Bohr
Dalton
Democritus
Rutherford
J. J. Thomson
Procedure:
1. On a piece of paper, draw a flow map consisting of five main boxes, one for each
scientist listed above.
2. Place the scientists’ names in the correct order. (NOTE: they are listed above in
alphabetical order, NOT chronological order!) Neatly write each scientist’s name
and the year associated with that person in the correct box.
3. Below each main box, you should add smaller boxes. Each small box should
contain only one fact. Include as many boxes as necessary to highlight and
discuss the main discoveries and/or theories the person is responsible for.
Bell Ringer
• What scientist expanded on the initial idea
of atoms?
• How do we know that electrons exist?
Parts of an Atom
• Atom = nucleus surrounded by one or more electrons
• Atoms are neutral (no charge) – same number of protons as electrons.
• Majority of the atom is empty space. – If nucleus were the size of a pencil eraser, the closest electron
would be 100 yards away!
• Subatomic Particles– Protons (+)
– Neutrons (0)
– Electrons (-)
• Nucleus: Tightly packed
Protons & Neutrons
• Electrons Orbiting nucleus
@ speed of light!!
HELIUM ATOM
+N
N
+
--
proton
electron neutron
Shell
ATOMIC STRUCTURE
Particle
proton
neutron
electron
Charge
+ charge
- charge
No charge
1
1
nil
Mass
Atomic Number• Atomic Number = # of Protons
• Each Element in the Periodic Table has a
different number of Protons, therefore each
element has a different, unique, atomic number.
When reading the Periodic table notice each element has a unique 1 or 2 letter symbol and “big” & “small” number listed
ATOMIC STRUCTURE
the number of protons in an atom
the number of protons and neutrons in an atom
He2
4 Atomic mass
Atomic number
number of electrons = number of protons
***IF the atom is neutral ****
Can you read these?
Electrical Atomic Charge
• Remember that Atoms are neutral (no charge)
• So, the # of protons = # of electrons
• If you know the Atomic #, you know the # of
Protons and also the # of Electrons!!
For example:
Carbon has an atomic # of 6, it therefore has 6 Protons which has an electrical charge of +6, to make the atom neutral we need 6 negative charges found in the 6 electrons orbiting the nucleus.
How many Neutrons are there?• Remember:
– The Atomic # = the # of Protons
– The Atomic mass = The # of both Protons & Neutrons.
– Therefore, if you subtract the Atomic # (the number of Protons) from the Atomic mass (the number of both Protons & Neutrons) what is left over must be the number of Neutrons!!
For Example w/ Carbon:
Atomic Mass-Atomic # = # Neutrons
Atomic Mass = 12, Atomic # 6
12 – 6 = 6
Therefore there are 6 neutrons present in the Carbon nucleus
If you don’t believe me… just count for yourself.
What is an Isotope?Atoms with the same
number of protons, but a
different number of
neutrons.
“Same number of protons”
means same atomic
number, which means
same element.
“Different number of
neutrons” means different
mass numbers.
Mass number (atomic mass)
Atomic Mass = the total # of Protons & Neutrons
( we don’t worry about the mass of the electrons
since they have almost no mass)
Isotopes
• Can sometimes be represented with
dashes and numbers that follow the
element.
• C-14
• Pu-246
• O-16
• O-17
Heavy Water
• Video clip
• Information about heavy water
Review
• How many protons and neutrons are there
in an atom of 115B?
A 5 protons and 6 neutrons
B 5 protons and 11 neutrons
C 11 protons and 5 neutrons
D 11 protons and 6 neutrons
• How many neutrons are in an element of
Pu-246?
– A. 94
– B. 150
– C. 152
– D. 246
Ions
• Ions are atoms that have a charge.
• In this case, protons do not equal
electrons.
• Number of electrons can change based on
charge of atom.
• Negative charge means the addition of an
electron.
• Positive charge means you lost an
electron.
• How many protons, neutrons, and
electrons?
N +
F -
Abundance of Isotopes
• Remember: Isotopes are atoms of the same element
with different numbers of neutrons
• For example, the abundance of Carbon in nature may be
97% C-12, 1% C-13, and 2% C-14.
• This means that most of the carbon exists as C-12 and
just a few atoms exist as other isotopes.
Average Atomic Mass
• You may notice that many of the atomic masses on the
periodic table are in decimal numbers.
• This is not because these elements have partial
neutrons!
• This is because that number is the average atomic mass
of the element
Average Atomic Mass
How to Solve for Average Atomic Mass
• Say you have a sample of nitrogen atoms. 95%
are N-14, 1% are N-13, and 4% are N-15.
• You can solve for average atomic mass by
multiplying by the percentages and adding the
total.
(.95)x14 + (.01)x13 + (.04)x15 = 14.03
• The average atomic mass for Nitrogen is 14.03
amu.
You Try
• You have a sample of Chlorine. 50% is Cl-35,
20% is Cl-34, 20% is Cl-36, and 10% is Cl-37.
What is the average atomic mass?
(.50) x 35 + (.20) x 34 + (.20) x 36 + (.10) x 37=
35.2 amu
Beanium Lab
• Today you will be allowed to pick your own
groups of three.
• You will not need goggles for this lab.
• You may write on the answer sheet (1 per
group)
• I need to see 3 different handwritings for full
credit.
• Tip: Make sure you zero the scale with your
weigh boat!
Bell ringer 9/23/14
1. Explain Oxygen-17 and Oxygen-18.
2. How many protons do they each have?
3. How many neutrons do they each have?
Symbol Atomic # Mass # # of
Protons
# of
Electrons
# of
Neutrons
Hg 80 201
Mo 42 96
29 29 35
C 14
15 31
Pb 208 82
Na 11 13
Bellringer
Based on the number of neutrons, what can
you conclude about these elements?
Neils Bohr, 1913• From a study of Hydrogen, concluded that
an electron travels around the nucleus in
circular paths called orbits
• Each pathway represents an energy
level.
• Only orbits of certain energies are allowed.
Electrons can’t exist between orbits.
• Like rungs on a ladder
Bohr’s model animation
Niels Bohr• Level closest to nucleus has lowest energy
• Energy must be added for an electron to move up a
level. Energy is released when an electron moves
down.
ATOMIC STRUCTURE
Electrons are arranged in Energy Levels or
Shells around the nucleus of an atom.
• first shell a maximum of 2 electrons
• second shell a maximum of 8 electrons
• third shell a maximum of 18 electrons
Bohr’s Planetary Model – looks like
planets orbiting the sun!!!
How many electrons are present in each orbit?
2
8
18
32
Electron Cloud Model – advanced
from Bohr’s model• Bohr’s “orbits” are now “principal energy levels”.
• Bohr was incorrect in assuming that electrons moved like planets in a solar system.
• The Electron Cloud model shows the MOST LIKELYlocation of electrons in an atom!! (these are not precise since it’s all based on probability!!)– Think of a propeller on an airplane...you can see the blades
when they aren’t moving…when it is moving you see only a blur…this is like the electron cloud model!!
• The number of electrons in each principal energy level is still correct
• 2, 8, 18, 32
• More atoms shown with Bohr’s model
• Which of the following provides the best
analogy for an electron in an atomic
orbital?
• a. a bee buzzing from flower to flower in a
garden
• b. a bird flying high in the sky
• c. an ant crawling on the surface of a leaf
• d. a bee buzzing inside a closed jar
Quantum Mechanical Model
(electron cloud model)
Bohr Model
Atomic Orbitals
• Orbital – a region of space around the
nucleus where an electron is most likely to
be found (think of a map of the school and
dots that mark your location every 10
minutes)
• Electron configuration – the arrangement of
electrons in the orbitals of an atom
– Most stable – electrons are in orbitals with the
lowest possible energy
Remember!!
• When electrons move to a higher orbital
they GAIN energy!!
• When electrons move to a lower orbital
they RELEASE energy!!
Structure of the Atom
subatomicparticles
Proton p+
Positive chargeIn nucleusmass =1
Neutron no
Neutral chargeIn nucleusmass = 1
Electron e-
Negative chargeIn electron cloudmass = 1/1840
Bell Ringer
• Please draw electron cloud models (Bohr
models) for these elements: (please make sure you
show # of protons and neutrons as well!!)
1. Nitrogen
2. Argon
