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Introduction to Periodic Table (Science)

INTRODUCTION TO
THE PERIODIC TABLE
Atomic Number ● Symbol ● Atomic Weight
Element ● Compound ● Mixture

I am Dmitri Mendeleev!
I made the PERIODIC TABLE !

Russian Chemist who first published the first
version of a systematically organized periodic
table of elements. This table was arranged in
order of increasing atomic mass and was the
basis of the currently used periodic table.
He organized the elements into columns
groups or families and rows called periods
series. This arrangement observed what is now
known as periodic law, which asserts that when
elements are arranged according to increasing
atomic mass, their properties will follow a
periodic pattern.

German chemist who recognized
the similarities in the chemical
properties of some triads of
elements, upon which
observation he established his
law of triads.
However, the limited number of
element triads could not support
his hypothesis.
Johann Wolfgang Döbereiner

German Chemist who
published a periodic table in
1864 where there then
known 44 elements were
organized based on the
valency of the elements.
He later published in 1870 an
improved version that
related atomic volume and
atomic number.
LOTHAR MEYER

Proposed the laws of
octaves which
recognized the
periodic properties of
every eighth element
in his list.
JOHN AR NEWLANDS

What is the PERIODIC TABLE?
◦Shows all known
elements in the
universe.
◦Organizes the
elements by chemical
properties.

How do you read the
PERIODIC TABLE?

What is the ATOMIC NUMBER?
◦The number of
protons found in the
nucleus of an atom
Or
◦The number of
electrons surrounding
the nucleus of an
atom.

What is the SYMBOL?
◦An abbreviation
of the element
name.

What is the ATOMIC WEIGHT?
oThe number of protons
and neutrons in the
nucleus of an atom.

How do I find the number of protons,
electrons, and neutrons in an element
using the periodic table?
◦ # of PROTONS = ATOMIC NUMBER
◦ # of ELECTRONS = ATOMIC NUMBER
◦ # of NEUTRONS = ATOMIC _ ATOMIC
WEIGHT NUMBER

How do I find the number of protons, electrons, and neutrons in an
element using the periodic table?
p n e A Z Isotopes
6 6 6 6
12

How do I find the number of protons, electrons, and neutrons in an
element using the periodic table?
Number of Electrons = 56
Number of Neutrons = 14
Name of Element = ______
Mass Number = ______
Number of Protons = 24
A = ______
Z = 50
Number of Electrons = 34

Elements, Compounds, and
Mixtures

What is an ELEMENT?
oA substance
composed of a single
kind of atom.
oCannot be broken
down into another
substance by
chemical or physical
means.

What is a COMPOUND?
oA substance in
which two or more
different elements
are CHEMICALLY
bonded together.

What is a MIXTURE?
◦Two or more
substances that
are mixed
together but are
NOT chemically
bonded.

The modern periodic table has 118 elements officially recognized
by the International Union of Pure and Applied Chemistry (IUPAC).
These elements are arranged in the periodic table in a way that
they can easily be classified and identified. The A group (in longer
columns) are classified as representative elements or main group
elements; the B group elements (in shorter columns) are called
transition elements.
Elements in the periodic table are also labeled vertically in groups
or families, and horizontally in periods or series.

1. ALKALI METALS (GROUP 1A)
◦They have only one electron in their
valence shell (ns1), which makes them
very reactive because they can easily
lose this electron to form their ions with
a charge of +1.

2. ALKALINE EARTH METALS
(GROUP IIA)
◦They have two valence electrons (ns2),
which they can lose to form +2 ions.
These metals are also silver-colored and
soft, with low densities, and melting and
boiling points. They also react with water
to form strongly alkaline hydroxides.

3. TRANSITION METALS
◦These are “typical” metals
◦Middle “chunk” of periodic table.
◦Group III to XII
◦ .

4. OTHER GROUPS
a. Group 3A (Boron Group)
b. Group 4A (Carbon Group)
c. Group 5A (Prictogens or Nitrogen Group)
d. Group 6 A (Chalcogens or Oxygen Group)
e. Group 7 A (Halogens)

5. HALOGENS
Most reactive non metals.
Reacts with metals to form salt.
Group 17 of Periodic Table.

6. GROUP 8A (NOBLE GASES)
Considered as non metals.
The noble gases are relatively inert; they rarely form compounds with
other elements. They can exist as monatomic gases.
Group 18 of the periodic table of element.

Bohr’s Model of the Atom
◦In 1913, Niels Bohr, a Danish physicist
working in Rutherford’s laboratory,
proposed a quantum model for the
hydrogen atom that seemed to answer
this question.
◦ This model correctly predicted the
frequency lines in hydrogen’s atomic
emission spectrum.

◦The lowest allowable
energy state of an atom is
called its ground state.
◦When an atom gains
energy, it is in an excited
state.

Bohr’s Model of the Atom
◦Each orbit was given a number,
called the quantum number.
◦Bohr orbits are like steps of a ladder,
each at a specific distance from the
nucleus and each at a specific energy.

QUANTUM
MECHANICAL MODEL
OF ATOM

Determines the
allowed
energies an electron
can have
and how likely it is to
find the electron
in various locations
around the nucleus.

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Introduction to Periodic Table (Science)

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