17. The History of the Modern Periodic
Glenn T. Seaborg
1912 - 1999
Table
He is the only person to have an element
named after him while still alive.
"This is the greatest honor ever
bestowed upon me - even better, I think,
than
winning the Nobel Prize."
18. Key in 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.
19.
20. Key in the Periodic Table
Atomic Number
This refers to how many protons an atom
of that element has.
No two elements, have the same number
of protons.
Wave Model
21. Key in the Periodic Table
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.
This is a helium atom. Its atomic mass is 4
(protons plus neutrons).
What is its atomic number?
22. Key in the Periodic Table
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.
23. Key in the Periodic Table
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.
24. Key in the Periodic Table
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).
25. Key in the Periodic Table
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.
26.
27. Key in the Periodic Table
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.
28. Key in the Periodic Table
Where to elements come from?
The ‘Big Bang’ theory suggests that all the
fundamental particles in the universe were
formed over a very short time (a few seconds or
less) in a huge explosion that occurred some 15
billion years ago.
Explain the fourth state of matter – plasma.
How is He formed?
What is the difference between nuclear fission
and nuclear fusion?
29. Key in the Periodic Table
Where to elements come from?
Once a star has converted a large fraction of
its core mass to iron, it has almost reeached
the end of its life
The core of the star then begins to cool,
causing a violent gravitational collapse, or
implosion.
Eventually the star explodes, spreading its
products throughout the universe.
An exploding star is called a supernova
A supernova can produce heavier elements
up to the size of the iron nucleus by nuclear
fusion reactions. Larger stars can produce
heavier atoms
32. Periodic Table Geography
The elements in any group of the
periodic table have similar physical and
chemical properties.
The vertical columns of the periodic
table are called GROUPS, or FAMILIES.
33. Periodic Table Geography
Periodic Law
When elements are arranged in order of
increasing atomic number, there is a
periodic pattern in their physical and
chemical properties.
40. Groups and Block
Based upon the electron configuration of the
elements the table can be divided into four
blocks. These blocks represent the different
sublevels of electron configuration.
Group A elements are called
representative elements
Group B elements are called transition
elements.
41. Groups and Block
The s and p block elements
are called
REPRESENTATIVE ELEMENTS.
The d block elements
are called
TRANSITION ELEMENTS
42. Groups and Block
The s-block elements:
Groups 1-2
Electron configuration: ns1,2 (valence
electrons in the s subshell)
Contains the alkali metals (Group 1), and
alkaline-earth metals (Group 2)
Very reactive metals; Group 1 is more
reactive than Group 2, but both do not
exist in nature as free elements because
they are too reactive.
He has a filled s subshell of the innermost
K shell of the atom rendering it
unreactive.
43. Groups and Block
The d-block elements:
Groups 3-12
Electron configuration: (n-1)d1-10ns0-2
(valence electrons in the p subshell)
transition elements: typical metallic
properties
Good Conductors of electricity and have a
high luster; less reactive than the s-block
elements; many exist in nature as free
elements.
44. The f-block elements:
Groups and Block
Lanthanides and Actinides
Between Groups 3 and 4.
Between Periods 6 and 7.
14 in each; highly similar properties;
resemble Group 2 elements.
f subshells progressivley filled
47. 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.
48. 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
49. Properties of Metalloids
Silicon (Si)
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.
63. HYDROGEN
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.
64. 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.
65. 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.
66. Alkaline Earth Metals
They are never found
uncombined in nature.
They have two valence
electrons.
Alkaline earth metals include
magnesium and calcium,
among others.
67. 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.
68. 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.
69. 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.
70. 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).
71. 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.
72. 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.
73. 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.
74. Noble Gas
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.
75. 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.