Download Agenda 11/2/2016

Agenda 11/2/2016
Slip Quiz
Left Step Periodic table - labelling?
Electron Configurations and Energy Levels
Trends in Properties in the Periodic table explaining the patterns (atomic radii notes)
Naming Elements Announcement memo
Homework and What’s coming up
Slip Quiz
1. Identify each element - explain your
reasoning.
2 2 1
a)1s 2s 2p
b) [Ar]4s
1
Slip Quiz
1. Identify each element - explain your
reasoning.
2 2 1
a)1s 2s 2p
b) [Ar]4s
1
Add exponents to find there are 5
electrons - therefore Boron (atomic
Slip Quiz
1. Identify each element - explain your
reasoning.
2 2 1
a)1s 2s 2p
b) [Ar]4s
1
Next element after [Ar] - therefore
potassium (or period 4, 1st element)
How can we remember the order of the orbitals?
Textbook suggests:
Practice/ familiarity
Left Step Periodic table -
Cut and stick (He above Be)
s-block elements
This is now going to be RHS of table:
Left Step Periodic table
Cut out p-block and
line up so atomic
numbers go in order
Stick on LHS of
s-block
Left Step Periodic table
Cut out d-block
and line up so
atomic numbers
go in order
Stick in position
Left Step Periodic table
Left Step Periodic table - check the order
Left Step Periodic table
1s
2s
3s
4s
5s
6s
7s
Left Step Periodic table
1s
2s
3s
4s
5s
6s
7s
Left Step Periodic table
2p
3p
4p
5p
6p
7p
Left Step Periodic table
2p
3p
4p
5p
6p
7p
Left Step Periodic table
3d
4d
5d
6d
Left Step Periodic table
3d
4d
5d
6d
s
bloc
Left Step Periodic table
1s
p block
2s
2p
3s
3p
4s
3d
4p
5s
4d
5p
6s
4f
5d
6p
7s
5f
6d
7p
8s
d block
f block
Compare quantum mechanical model to the Nuclear
Atom Model we were using:
nucleus
electron cloud
Electron Configurations continued:
Consider
sodium
Atomic number 11 (11 electrons)
1s22s22p63s1
(superscripts 2 +2 +6 +1 = 11, tell us total
number of electrons)
Orbital diagram:
Electron Configurations:
1) Atomic number 11 (11 electrons)
sodium
1s22s22p63s1
Orbital diagram:
Electron Configurations:
Atomic number 11 (11 electrons)
sodium
1s22s22p63s1
Orbital diagram:
Rotate so its
On a line
across the page
Gives us ...
Space saving version.
1s22s22p63s1 Or
[Ne]3s1
Electron Configurations:
1) Atomic number 11 (11 electrons)
sodium
1s22s22p63s1
Orbital diagram:
Energy level 1
Electron Configurations:
1) Atomic number 11 (11 electrons)
sodium
1s22s22p63s1
Orbital diagram:
Energy level 2
Electron Configurations:
1) Atomic number 11 (11 electrons)
sodium
1s22s22p63s1
Energy level 3
Orbital diagram:
Notice Na in
Period 3
A 2D Model for Size of atom visualization:
Representing each energy level with a ring. 3 energy
levels, getting further from nucleus (represented by 11+
for protons in nucleus) using “e-” for electrons.
level
1
e- 11+
e-
Model for Size of atom visualization:
level
2
3
e-eee- e- 11+ eeee- e-
Electrons in outermost energy level
called valence electrons
e-eee- e- 11+ eeeee- e-
Atomic radius vs. Atomic Number (take notes under graph)
Group trends in atomic radii
Atomic Radii (size of atoms) Main Group
Generally Atomic radius increases down a
group
Nuclear charge increases down a group
- electrons are added to successively higher
principal energy levels
- the orbitals are larger in size.
-
Generally Atomic radius increases down a
group
Nuclear charge increases down a group
- electrons are added to successively higher
principal energy levels
- the orbitals are larger in size.
- the increased distance offsets the greater pull of
the increased nuclear charge
- Also the electrons in the inner orbitals shield the
outermost electrons from the pull of the nucleus
Atomic Radii trend across a period
Generally Atomic radius decreases across
a period
Nuclear charge increases across a period
- electrons are added to orbitals in the same principal
energy level
-
Generally Atomic radius decreases across
a period
Nuclear charge increases across a period
- electrons are added to orbitals in the same principal
energy level
- Moving across a period the increased nuclear
charge increases the pull of the nucleus on the
electrons in the orbitals in that energy level
- the outermost electrons are pulled closer to the
nucleus and atomic radius gets smaller
Note on atomic radius - measuring it
- Electron cloud - based on probability - does not
have a clearly defined edge
- Atomic size defined by how closely an atom lies to
a neighboring atom - tends to vary in different
substances
- For metals - atomic radius is defined as half
distance between adjacent nuclei in a crystal of the
element
Atomic radius vs. ionic radius
An ion is an atom or bonded group of atoms
that has a positive or negative charge.
e-eee-
e- 11+ ee- eee- e-
Sodium atom
Sodium ion Na+
Electrically neutral
11+ - 10- = +1 charge
The Octet Rule
Atoms tend to gain, lose or share electrons in
order to acquire a full set of eight valence
electrons.
Electron configurations like those of the Noble gases
with filled s and p orbitals of the same energy level are
unusually stable. (Note that Helium has only 2 valence
electrons, but that is because the 1st energy level can
only accommodate 2 electrons in its 1s orbital.)
The Octet Rule
Electron configurations like those of the Noble gases
with filled s and p orbitals of the same energy level are
unusually stable. (Note that Helium has only 2 valence
electrons, but that is because the 1st energy level can
only accommodate 2 electrons in its 1s orbital.)
Useful for determining the type of ions that elements
are likely to form.
What kind of ion is a reactive element on right hand
side of PT - a nonmetal, likely to form?
Bromine
Or
1s22s22p63s23p64s23d104p5
1s22s22p63s23p63d104s24p5
Inner electrons
x
outermost, valence electrons
7 valence electrons
x
x
35+
xx
x
x
What kind of ion is a reactive element on right hand
side of PT - a nonmetal, likely to form?
Bromine if it gains an electron, now Br-, a bromide ion
Notice complete octet of electrons in outermost energy level
xx
x
x
35+
xx
x
x
35+ (36 - ) = -1
Homework
Read the IUPAC announcement about the names of the 4 new
elements that will complete the 7th period on the periodic table.
Write in those symbols on the Left step periodic table we made in
class today, you which has blank spaces for these elements
(replace the Uu ones that were place holders if necessary).
Do additional research to find any remaining element symbols
and names - and make a note on the back of the paper where
you found your information and when the elements were named.
This paper will be graded at the start of class on Friday.
Heads Up - What’s coming up
Friday - Electron dot diagrams/structures, Long form periodic
table, notes on explaining periodic trends in ionization energy
and electronegativity, Ch5 Notes.
Study Guide for Test - to do over weekend
Tuesday - Review - including graphing on test
Thursday - Unit 3 Periodic Table and Electrons test