Transcript Bonding and the Periodic Table

Periodic
Table and
Periodic
Trends
Chapter 14
Periodic Table
• A table that organizes the elements in
order of increasing ________ ________
and by similar chemical and physical
properties
• ___________ ____________, Z
– The number of _________ in the nucleus of
an atom.
– It determines the __________ of the atom.
Periods / Series
• ______ on the periodic
table
• Represent the ________
that the valence electrons
occupy.
• Valence Electrons
– ____________ electrons in
an atom.
– The electrons that are lost,
gained, or shared in chemical
reactions.
– The _________ ________
________ in an element's
outer shell determines the
chemical properties of that
element.
Li (Z=3)
Be (Z=4)
B (Z=5)
Groups/Families
• Columns
• All elements in the same
group have the same
number of ________
_________, and therefore
have similar
__________ properties.
• Some groups have
special names
Li (Z=3)
Na (Z=11)
K (Z=19)
Special Groups
•
•
•
•
Group 1 Group 2 Group 7 Group 8 -
•
In addition some
regions of the
periodic table have
special names.
Metals
• Located on the _____
side of the periodic
table.
• _______ ________
________ in chemical
reactions.
• ________, ________,
________, ________
• Transition metals.
Nonmetals
• Located on the _____
side of the periodic
table.
• ______, ________
• _______ ______ in
chemical reactions.
• ________ ______:
Every atom wants
__ valence
electrons.
Metalloids
• Located on the stairstep line.
• Have metallic and
nonmetallic properties.
• B, Si, Ge, As, Sb, Te,
and Po
Blocks
• Based on electron
configurations
• Named after the
sublevels that are being
filled.
Na (Z=11)
O (Z=8)
Cu (Z=29)
Representative Elements
• ___-block and ___block elements.
• Lewis Dot Diagrams
– Dots represent v. e– One dot per v. e– Only used with rep.
elements
Development of the PT
• Дмитрий Менделеев
• Lothar Meyer
• Henry Moseley
Periodic Trends
• A ________ ____________ variation in
elements’ properties due to regular variations in
atomic structure.
•
•
•
•
_____________ ___________
_____________ ___________
_____________ ___________
_____________
Atomic Radius
• The “______” of an atom.
• Determined by the ________
_________.
• There are different ways to
define atomic radius.
• 1/2 the distance between two
bonded nuclei.
Trend in Atomic Radius
Trend in Atomic Radius
• _________ across a period.
– Adding protons which pull the electrons in.
• __________ down a group.
___________ Radius
– Core electrons “shield” the outer electrons from the attractive
force of the nucleus.
____________ Radius
Ions, Cations, and Anions
• Ion
– An atom that has ______ or _______ electrons.
– A _________ atom*
• Cation
– A ____________ charged ion.
– An atom* that has _______one or more electrons.
• Anion
– A __________ charged ion.
– An atom* that has gained one or more electrons
Ionic Radius
Ionic Radii. (2008). NCSSM
D.E.T T.I.G.E.R. (chemistry,
periodic trends, ionic radii)
[Chemistry Animations and
Slides for Math and Chemistry].
Retrieved April 25, 2009, from
North Carolina State School of
Science and Mathematics
Distance Education
Technologies Web
site:
http://www.dlt.ncssm.ed
u/tiger/
Ionic Radius
• Cations are _______than the parent atom.
– The __________ to ___________ ratio ___________ and the
attraction on the remaining electrons _____________.
• Anions are _________ than the parent atom.
– The ___________ to __________ ratio __________ and the
attraction on the electrons ______________.
• Isoelectronic
Ionization Energy
• The _________ ________ needed to
_________ an electron from a ground
state ________ atom or ion.
Na(g)  Na (g)  e
Na(g)  Na (g)  e
Na (g)  Na2 (g)  e
I1  496
I2  4560
Succesive Ionization Energies
• First Ionization Energy, I1

Na(s)  Na (g)  e

I1  496 kJ/mol
• Second Ionization Energy, I2

Na (g)  Na (g)  e
• I1 < I2 < I3 <…
2

I2  4560 kJ/mol
Successive IEs
Trends in Ionization Energy
• ____________ across a period
– Atomic radius ____________ and the pull on
the electrons ___________.
– Smaller atoms have a greater attraction for
electrons, thus a higher ionization energy.
Trends in Ionization Energy
• ____________ down a ___________
– Adding more ________ _______ = more _______,
and the size of the atom __________.
– As the size of the atom increases the “pull” on the
electrons decreases and thus ionization energy
decreases
Irregularities in IE
Electronegativity
• The ability of an atom in a molecule to
__________electrons to itself.
• Can be used to predict how equally electrons are shared
in a bond.
• Calculate the electronegativity difference.
• Values range from 0 to 4
Difference
Bond Type
What’s happening
0 to 0.4
Nonpolar covalent
Equal sharing
Between 0.4 and 1.7
Polar covalent
Unequal sharing
Greater than 1.7
Ionic
Electron transfer
Trends in Electronegativity
____________across a _____________
– Atomic radius _________ and the pull on the electrons
__________.
– Smaller atoms have a greater _________ for electrons, thus a
higher ___________.
Trends in Electronegativity
• ____________ down a __________
– Adding more _______ _______ = more _________,
and the size of the atom increases.
– As the size of the atom __________, the “pull” on the
electrons ____________ and thus electronegativity
___________.