لخّصلي

Chapter 3 details the periodic classification of elements, covering its history and the organization of the modern periodic table into periods (rows) and groups (columns). The table is further divided into blocks (s, p, d, f) based on electron subshells. Element location is determined by atomic number and mass. Metals, nonmetals, and metalloids are categorized based on their properties and periodic table placement. Key element families (alkali metals, alkaline earth metals, transition metals, lanthanides, actinides, metalloids, halogens, noble gases) are described, highlighting their properties and group locations. The chapter also explains periodicity in physicochemical properties like electronegativity, atomic radius, and ionization energy, providing examples and exercises to predict element properties based on their periodic table position. Applications include writing electronic configurations and predicting element locations.

C H E M I S T R Y C O U R S E S C H A P T E R 3
The Periodic
Classification of
Elements
N e
PY
Mo Te Ku Kh Rd Aged I n Su So Te
W Re O u
N 4 P i n Sm
History
o f
P e r i o d i c T a b l e
The Modern Periodic Table's Organization
Periods
These rows are referred to as "periods"
and are labeled numerically from 1 to 7.
Groups
The vertical columns known as
"
groups," numbered from 1 to 18 (older
periodic tables employed Roman
numerals for this purpose).
Families of the Periodic Table
Columns of elements are called
groups or families. Elements in
each family have similar but not
identical properties.
Periodic Table Blocks of Elements
The periodic table is divided into several
blocks based on the type of subshell being
filled with electrons. These blocks are named
after the subshells they represent
How do you find the location of an element on the
periodic table using the atomic number and
mass?
application
Write the electronic configuration for 𝟏𝟒𝑺𝒊 , 𝟒𝑩𝒆 , 𝟏𝟐𝑴𝒈, 𝟑𝟓𝑩𝒓 , 𝟏𝟏𝑵𝒂 ,
𝟏𝟓𝑷, 𝟏𝟕𝑪𝒍, 𝟖𝑶, 𝟐𝟎𝑪𝒂, 𝟏𝟗𝑲, 𝟕𝑵 then predict their location in the periodic table.
How do you find the location of an element on the periodic table
using the atomic number and mass?
THINGS TO KEEP AWARE
Metals (Métal in French): Elements located on the left and center
of the periodic table are typically metals. They have properties
such as high electrical and thermal conductivity, malleability,
ductility, and a tendency to lose electrons to form cations.
Nonmetals (Non-métal in French): Elements on the upper right of
the periodic table are typically nonmetals. They have properties
like low electrical and thermal conductivity, brittleness, and a
tendency to gain electrons to form anions.
Metalloids (Métalloïde in French): Metalloids are elements that
exhibit properties of both metals and nonmetals. They are found
along the "staircase" line on the periodic table, separating
metals from nonmetals. Examples of metalloids include boron,
silicon, and germanium
Which Elements Fall Into Which
Block?
Element blocks are named for their
characteristic orbital, which is
determined by the highest energy
electrons:
S-block: The first two groups of the
periodic table, the s-block metals:
Are either alkali metals or alkaline
earth metals.
Are soft and have low melting points.
Are electropositive and chemically
active.
Which Elements Fall Into Which
Block?
Families of the Periodic Table
The Alkali metals are comprised of group 1 of the periodic table and
consist lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium
(Cs), and francium (Fr). These metals are highly reactive and form ionic
compounds as well as many other compounds. Alkali metals all have a
charge of +1 and have the largest atom sizes than any of the other
elements on each of their respective periods
Families of the Periodic Table
Alkali Earth Metals are located in group 2 and consist of beryllium
(Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba),
and radium (Ra) . Unlike the Alkali metals, the earth metals have a
smaller atom size and are not as reactive. These metals may also
form ionic and other compounds and have a charge of +2.
Families of the Periodic Table
The transition metals range from groups IIIB to XIIB on the periodic table.
These metals form positively charged ions, are very hard, and have very
high melting and boiling points. Transition metals are also good
conductors of electricity and are malleable.
Families of the Periodic Table
Lanthanides and Actinides, form the block of two rows that are placed at the
bottom of the periodic table for space issues. These are also considered to be
transition metals. Lanthanides are form the top row of this block and are very
soft metals with high boiling and melting points. Actinides form the bottom
row and are radioactive. They also form compounds with most nonmetals. To
find out why these elements
Families of the Periodic Table
Metalloids are located along the staircase separating the
metals from the nonmetals on the periodic table. boron
(B), silicon (Si), germanium (Ge), arsenic (As), antimony
(Sb), tellurium (Te) and Polonium (Po) all have metal and
nonmetal properties. For example, Silicon has a metallic
luster but is brittle and is an inefficient conductor of
electricity like a nonmetal. As the metalloids have a
combination of both metallic and nonmetal
characteristics, they are intermediate conductors of
electricity or "semiconductors".
Families of the Periodic Table
Halogens are comprised of the five nonmetal elements
Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I) and
Astatine (At). They are located on group 17 of the periodic
table and have a charge of -1. The term "halogen" means
"salt-former" and compounds that contain one of the
halogens are salts. The physical properties of halogens vary
significantly as they can exist as solids, liquids, and gases at
room temperature. However in general, halogens are very
reactive, especially with the alkali metals and earth metals
of groups 1 and 2 with which they form ionic compounds.
Families of the Periodic Table
The noble gases consist of group 18 (sometimes reffered to as
group O) of the periodic table of elements. The noble gases have
very low boiling and melting points and are all gases at room
temperature. They are also very nonreactive as they already
have a full valence shell with 8 electrons. Therefore, the noble
gases have little tendency to lose or gain electrons.
Periodicity of the physicochemical
properties of elements
Electronegativity
Electronegativity is a measure of the
ability of an atom to attract the
electrons when the atom is part of a
compound. . All elements are
compared to one another, with the
most electronegative element, fluorine,
being assigned an electronegativity
value of 3.98. Fluorine attracts
electrons better than any other
element.
Atomic radius
is defined as one-half
the distance between
the nuclei of identical
atoms that are bonded
together.
Ionization energy
I is the energy required to remove
an electron from a specific atom. It
is measured in kJ/mol, which is an
energy unit, much like calories. For
any given atom, the outermost
valence electrons will have lower
ionization energies than the inner-
shell kernel electrons. As more
electrons are added around a
nucleus, the outer electrons
become shielded from the nucleus
by the inner shell electrons. This is
called electron shielding
Periodicity of the physicochemical
properties of elements

1. Determine the period and column of the periodic table to which
   each element.
   He(z=2), C (z=6), Be (z=4), Na (z=11), Mg (z=12), P (z=15),
   Ar (z=18)


2. Predict the order of increasing covalent radius for
   Nitrogen (N Z=7), Oxygen (O=8), Fluorine (F=9)


3. Based on their positions in the periodic table, predict
   which has the largest first ionization energy: Mg=12, Ba=56,
   B=5, Be (z=4), O=8.
   The first ionization energy generally increases from left to right across a period in the periodic
   table and decreases down a group. So, based on their positions in the periodic table:
   The element with the largest first ionization energy is oxygen (O), followed by boron (B), then
   magnesium (Mg), and finally, barium (Ba). Therefore, oxygen has the largest first ionization
   energy among the given elements.
   Demonstrate that rubidium (37Rb), yttrium (39Y), and antimony (51Sb)
   belong to the same period and that antimony, arsenic (33As), and
   phosphorus (15P) belong to the same group, then give to each element its
   atomic radius (ra), ionization energy (Ei), and electronegativity (X) taken
   from the following values: