Transcript Periodic Table continues - Barnegat Township School District

Honors Chemistry Chapter 6
Electron configuration and the
Periodic Table
 Relationship between period length
and sublevels being filled
 “Blocks” on the table – be able to
identify
 s,p,d,f
Group 1
 All have ns1 outer shell notation
 Group 2
 All have ns2 outer shell notation
 The value for n tells you what period it is in,
the superscript lets you know the group
d block elements
 Groups 3 – 12
 (n-1)dns
 Add together the outermost d and s
electrons and it will equal the group
number
p block
 Groups 13 – 18
 (with groups 1 and 2 are called the “main group” or
“representative” element)
 general electron configuration for p block is ns2np
 Metals, metalloids, and nonmetals contained in this
block.
f block
 Lanthanide series
 Actinide series
 f sublevel being filled
 Lanthanide series – shiny metals similar in reactivity
to Group 2 – alkaline earth metals
 Actinide series – all radioactive. Thorium through
neptunium are found naturally on Earth. Others are
laboratory made.
TRENDS IN ATOMIC RADII
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Gradual decrease as atomic number increases
across a period
Caused by the increasing positive charge of the
nucleus
In general, atomic radii of the main group
elements increases down a group (as a.n.
increases)
Radius resulting when an atom forms an
ion
 Cation – positive ion. Results when a
neutral atom loses electrons. Radius
decreases
 Anion – negative ion. Results when a
neutral atom gains electrons. Radius
increases


The energy required to remove one electron
from a neutral atom of an element (first
ionization energy)

A + energy  A+ + e-

Forms an “ion” – atom or group of bonded
atoms that has a positive or negative charge


Process called “ionization”
Pg. 143 Table of ionization energy




In general, first ionization energies increase
as atomic number increases across a period
for main-group elements
Metals – lose their electrons easily (reason for
high reactivity)
Noble gases – highest i.e. values. Do not lose
electrons easily – (accounts for low reactivity)
Increased nuclear charge accounts for
increase in i.e.


Among the main-group elements, i.e.
generally decreases down the groups
Removed more easily because they are in
higher energy levels, farther from the nucleus
– able to overcome nuclear charge
ionization energy
 Always higher than the first
The energy change that occurs when an
electron is acquired by a neutral atom
 Most atoms release energy when this
happens
 A + e-  A- + energy
 Quantity of energy represented by a
negative number





Some atoms must be “forced”
A + e- + energy  Athis quantity represented by a positive
number
Ion made this way is very unstable – will lose
the added electron spontaneously



Halogens gain electrons most readily –
reason for high reactivity
In general, as electrons are added to the
same p sublevel with the same period,
electron affinities become more negative
There are exceptions to this
 Not as regular as trends for i.e.
 As a general rule, electrons add with
greater difficulty down a group
Are the electrons available to be lost,
gained, or shared in the formation of
chemical bonds
Often located in incompletely filled mainenergy levels
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Fire water
periodic trends tutorial 1
periodic trends tutorial 2