Transcript Atomic-theories3

CHEMISTRY
ATOMIC THEORIES 3
(PERIODIC PROPERTIES)
Hugo Ortiz Moreno
Escuela de Ingeniería
Universidad del Valle de México
Outcome:
1. You will remember the definition
and objective of chemistry.
2. You will be able to describe the
evolution of the atomic models.
3. You will be able to develop the
electronic configuration of any
element.
4. You will be able to predict the
behavior of an atom by its
position in the periodic table.
Key words
Element
Atomic model
Bohr
Electron
Paired electrons
Unpaired electrons
Quantum
Quantum numbers
n, l, m, s values.
Electronic configuration
Period
Periodic table
Periodic properties
(electronegativity, ionization
potential, electronic affinity)
PERIODIC PROPERTIES
Group 1. Alkaline metals
Be = Beryllium
Mg = Magnesium
Ca = Calcium
Sr = Strontium
Ba = Barium
Ra = Radium
Less
electropositive
than
alkaline elements but they are
very reactive too.
Li = Lithium
Na = Sodium
K = Potassium
Rb = Rubidium
Cs = Cesium
Fr = Francium
Very
electropositive
and
reactive elements. They usually
form positive ions.
Group 2. Earth alkaline metals
Group 3 - 12. Transition
metals
Almost all of their compounds
are colored and they are very
useful in our daily life.
Guess where and how!
Group 17. The halogen
elements
Very
reactive
and
electronegative
elements.
They usually form negative
ions.
One hybrid classification.
Metalloid
Metalloids are some of the
elements that have best
contributed
to
modern
technologies development.
Guess where and how!
Metals
Nonmetals
Group 18. Noble gases
Very stable gases.
Guess why!
Lanthanides and Actinides
Lanthanides are named rare earth
elements too.
The actinides group is constituted
by radioactive elements with
atomic numbers 89 through 103. It
was first suggested by Glenn
Seaborg.
ACTIVITIES

Give the name, the
atomic number and the
electronic configuration
of the external shell of
the most electropositive
elements.

Give the name, the
atomic number and the
electronic configuration
of the external shell of the
most electronegative
elements.
The periodic parameters
(Atomic mass, Atomic size, Electronegativity,
Electron affinity and Ionization Potential)
• Atomic mass: The mass
of an isotope of a given
element.
• Atomic size: The size of
an element usually given
as a radii.
• Electronegativity:
the
tendency of an atom or
radical to attract electrons
in the formation of a
bond.
• Electron affinity: The
ability of an element to
accept an electron to
form an ion.
• Ionization
Potential:
The minimum energy
necessary to pick up an
electron from a gas state
atom in its basal state.
Atomic Sizes (in Angstroms, which is 10-10 meter) from Various Sources
1.58
0.3
1.2
Increases
0.98
n.a.
4.10 2.80
1.52 1.12
2.34 1.82 1.50 1.30 1.14 1.02
0.88 0.77 0.70 0.66 0.64 n.a.
1.5 1.40 1.35 1.60
4.46 3.44
1.86 1.60
3.64 2.92 2.46 2.18 1.94 1.76
1.43 1.17 1.10 1.04 0.99 n.a.
1.9 1.85 1.80 1.92
5.54 4.46 4.18 4.00 3.84 3.70 3.58 3.44 3.34 3.24 3.14 3.06 3.62 3.04 2.66 2.44 2.24 2.06
2.31 1.97 1.60 1.46 1.31 1.25 1.29 1.26 1.25 1.24 1.28 1.33 1.22 1.22 1.21 1.17 1.14 n.a.
2.0 2.00 1.95 1.97
5.96 4.90 4.54 4.32 4.16 4.02 3.90 3.78 3.66 3.58 3.50 3.42 4.00 3.44 3.06 2.84 2.64 2.48
2.44 2.15 1.80 1.57 1.41 1.36 1.3 1.33 1.34 1.38 1.44 1.49 1.62 1.4 1.41 1.37 1.33 n.a.
2.2 2.20 2.15 2.17
6.68 5.56 5.48 4.32 4.18 4.04 3.94 3.84 3.74 3.66 3.58 3.52 4.16 3.62 3.26 3.06 2.86 2.68
2.62 2.17 1.88 1.57 1.43 1.37 1.37 1.34 1.35 1.38 1.44 1.52 1.71 1.75 1.46 1.4 1.4 n.a.
2.7 2.20 2.2
Atomic diameter computed using quantum mechanical calculations, Periodic Chart of the
Atoms (1979), Sargent-Welch
Atomic radii and covalent radii, "Chemical Systems," Chemical Bond Approach Project
(1964), McGraw-Hill
Van der Waals radii, Handbook of Chemistry and Physics, 65th Ed. (1984), CRC Press and
"Chemical Systems"
Electronegativity in the periodic table
Activities
• Which element is the most
electropositive; C, N, S, O.
• Which elements have no
electronegativity defined;
Cl, H, Kr, Xe, P.
• Write your own conclusions
with a partner and share
them with the class. (only 5
min)