Download The Periodic Table and The Periodic Law

The Periodic Table and The
Periodic Law
Development of the Modern Periodic
Table

1.
2.
There were multiple people/scientist who contributed
to the making of the periodic table as we know it…..
Antoine Lavoiser – compiled a list of
the 23 elements known in the late
1790s.
John Newland – noticed that if the
elements were arranged according to
the atomic masses, the properties of
the elements were repeated.

He called it the “Law of Octaves”.
Development of the Modern Periodic
Table
3. Dimitri Mendeleev – is the person
credited with making the 1st periodic table
leaving spaces for the predicted elements
in future. (It was based on the atomic
masses)
4. Henry Mosley – he then rearranged the
periodic table based on atomic numbers
and their characteristics, it is used till this
date.
Modern Periodic Table (Recap)
Lavoiser – original 23 elements, 1790’s
 Newland – Arranged by atomic mass;
Law of Octaves – Properties repeated
 Mendeleev – Left spaces for future
elements
 Moseley – Arranged by atomic numbers
and characteristics (current version)

Break-up of Periodic Table
How is table arranged?
 What are the rows called?
 What are the columns called?
 What are groups?
 What are families?
Break-up of the Periodic Table

Periods – Rows of the periodic table are
called the periods. (7 periods at present)
Periodic Table

two rows below the periodic table are the
lanthanide and actinide series

these rows fit after #57 and #89

they are only at the bottom to keep the
width of the chart smaller
Break-up of Periodic Table
Period
Break-up of the Periodic Table

Groups/Family – Columns in the periodic
table are called the groups. There a total
of 18 but further classified:
All “A” groups – representative elements
 All “B” groups – transition element

Groups have similar properties
Break-up of Periodic Table
Break-up of the Periodic Table

Within the groups and periods there is
further classification:

Metals

Non-metals

Metaloids
Break-up of the Periodic Table
Within the groups and periods there is
further classification:

Metals – located on the left, center and
bottom of the periodic table.
Break-up of Periodic Table
Break-up of the Periodic Table
Metals



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Usually, solids at room temperature.
Solid at room temperature (all but Hg)
malleable- can be rolled or hammered into sheets
ductile- can be made into wire
high tensile strength- can resist breakage when
pulled
Lustrous – shiny most have silvery or grayish white
luster
Break-up of the Periodic Table
Within the groups and periods there is
further classification:
Metals – located on the left, center and
bottom of the periodic table.
 Non-metals – They are located on the right
side of the table.

Break-up of Periodic Table
Break-up of the Periodic Table
Non-metals
 Many are gases
 If in solid form, they are brittle
 They are poor conductors of heat and electricity
Break-up of the Periodic Table
Within the groups and periods there is
further classification:
Metals – located on the left, center and
bottom of the periodic table.
 Non-metals – located on the right side of the
table.
 Metalloids – located on the “staircase” seen
in the periodic table.

Break-up of Periodic Table
Break-up of the Periodic Table
Metaloids
Also, known as “semi-conductors”
 They exhibit properties of both metals and nonmetals.
 B, Si, Ge, As, Sb, Te
 all are solids at room temperature
 less malleable than metals but less brittle than
nonmetals

The s, p, d and f blocks

s-block elements – Groups 1 and 2 (1-A
and 2-A)
Group 1 (1-A) – are called Alkali metals
 Group 2 (2 – A) – are called Alkaline earth
metals


p-block elements – Groups 13 – 18 (3-A
=> 8-A)
Group 17 (7-A) – are called Halogens
 Group 18 (8-A) – are called Noble gases

The s, p, d and f blocks

d-block elements – are the B group
elements (Groups 3 – 12 or 1B – 8B)

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They are called transition metals
f-block elements – are also within the B
group placed at the bottom of the
periodic table.
They are known as the inner-transition
metals
 They are also classified as the Lanthanide
and Actinide series

Periodic Trends
What is an ion?
 An ion is a charged atom or molecule.
 It is charged because the number of
electrons do not equal the number of
protons in the atom or molecule.
 An atom can be positively charged or a
negatively charged depending if the
number of electrons in an atom is greater
or less then the number of protons in the
atom.

Ions
Periodic Trends
Periodic Trends
What is a trend?
 It is a characteristic that is repeated. (OR
the general course or prevailing
tendency)
 In the periodic table trends occur across
a period and down the group. For
example:
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The elements get less metallic across the period
The elements become larger in size down a group.
Periodic Trends
Atomic Radius: It is the distance from the
center of the nucleus to the outermost
energy level where there are electrons.
 It increases down the group. Why?



The principal energy level increases.
It decreases across the period. Why?

The energy level is the same but the
number of electrons increases and hence
the electrostatic attraction increases.

Pg. 163
Periodic Trends
Ionic Radius: It is the distance from the
center of the nucleus to the outermost
energy level where there are electrons in
an ion.
 Positive ions are small
 Negative ions are large
 Pg. 166

Periodic Trends

Ionization Energy (I.E.): It is the amount
of energy needed to remove an electron
from an atom. (pg. 167 – 168)

The amount of I.E. increases across a
period (that is left to right) WHY?


The more electrons in the outermost orbital
hence more electrostatic attraction
The amount of I.E. decreases down a group
WHY?

The electrons are further away form the nucleus
Periodic Trends

Electronegativity (E.N.): It is known as
the ability of an atom to attract electrons.
(pg. 169)
E.N. increases across a period
 E.N. decreases down a group

Noble gases are ignored.
 Fluorine has the largest E.N.
 Francium the smallest E.N.

Practice Problems
Which has a higher ionization energy?
1. Fe or Cu
2. Na or Rb
3. Ge or Ga
4. C or Si
Practice Problems
Which is bigger?
1. K or Li
2. B or Al
3. O or F
4. Fe2+ or Fe+
Practice Problems
Which has a greater electronegativity?
1. Ca or Sr
2. Cu or Ag
3. Al or Cl
4. F or N
Choose the element with the smaller
radius
1.
2.
3.
Chromium or tungsten
Cadmium or silver
Tin or antimony
Choose the element with the larger
ionization energy
1.
2.
3.
4.
Magnesium or aluminum
Lithium or potassium
Yttrium or scandium
Carbon or germanium
Choose the element with the smaller
electronegativity
1.
2.
3.
4.
Lead or Bismuth
Bromine or astatine
Gallium or phosphorus
Mercury or Gold