Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.
-
Upload
corey-stephens -
Category
Documents
-
view
220 -
download
3
Transcript of Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.
![Page 1: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/1.jpg)
Elements andIonic Compounds
Unit II: Intro to Formulas
![Page 2: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/2.jpg)
A. Element OR Compound?
Elements:Formulas only contain ONE symbol
Which means only ONE capital letter.Names are only ONE word long.
Compounds:Formulas contain two or more symbols.
Which means more than one capital letter.
Names are TWO words long.LPChem1415
![Page 3: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/3.jpg)
Elements: A Review
We already learned that:Most element formulas consist of the
element symbol and nothing more.(Al, Cu, Ne, Au, etc.)
Seven elements are “diatomic” and always pair up in the elemental state:
(H2, N2, O2, F2, Cl2, Br2, I2)Elements go by their own names
But sometimes Carbon is sneaky.LPChem1415
![Page 4: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/4.jpg)
LPChem1415
Compounds
There are different types of chemical compound. For this unit, we are only learning IONIC compounds:
Ionic compounds form by transfer of valence electrons.Valence electrons are the
outermost electrons in an atom.
This atom has lots of electrons.
But only ONE in its VALENCE.
![Page 5: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/5.jpg)
The periodic table
The table is organized so similar
elements are together.
Similar properties are usually due to
similar # of valence electrons.
![Page 6: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/6.jpg)
Groups of similar elements have special names:
![Page 7: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/7.jpg)
# valence electrons
increases, left to right:
12 345678
![Page 8: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/8.jpg)
Sodium has 1 valence electron
Chlorine has 7 valence electrons
12 345678
![Page 9: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/9.jpg)
LPChem1415
Lewis Dot Structures
Show ONLY valence electrons
Each electron is shown as a dot.Electrons come in pairs– top, bottom, left,
& right of symbol.
![Page 10: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/10.jpg)
LPChem1415
Valence Electrons & Stability
12 345678
Eight valence electrons = a “full octet”
Atoms with a full octet are the most stable
This is why the noble gases are “noble”
![Page 11: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/11.jpg)
LPChem1415
Valence Electrons & Stability
All other elements work to achieve a
“full octet” by gaining, losing, or
sharing electrons:
Atoms are like onions– the electrons come in layers.
The sodium now has zero electrons in the diagram, but there was
already a full octet in the next lower layer, so it is stable now.
![Page 12: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/12.jpg)
LPChem1415
Valence Electrons & Stability
Gaining or losing electrons gives the
atom a charge.
Charged particles are called IONS.If one atom loses electrons, another must gain
them.
Even tiny electrons are matter, and can’t be
created or destroyed!
![Page 13: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/13.jpg)
LPChem1415
Valence Electrons & Stability
An atom that loses electrons becomes
positively charged.
This is a cation.
(Subtracting a negative
makes a positive!)
![Page 14: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/14.jpg)
LPChem1415
Cations are Positive
![Page 15: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/15.jpg)
LPChem1415
Valence Electrons & Stability
An atom that gains electrons becomes
negatively charged.
This is an anion.Note: the name changes
to the “–ide” form when it
becomes negative!
![Page 16: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/16.jpg)
Barium is in column 2 and has 2
valence electrons
Sulfur is in column 16 and has 6
valence electrons
1 2 3 4 5 6 7 8
![Page 17: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/17.jpg)
To get full octets:
Barium must lose TWO electrons
Sulfur must gain TWO electrons
Key Point: Ion charge is based on how
many electrons must be gained or lost to
get a full octet.
![Page 18: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/18.jpg)
LPChem1415
Valence Electrons & Stability
Main Group Ion Charges
1+
2+ 3+ 4± 3- 2- 1-
0
![Page 19: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/19.jpg)
Form because opposite charged ions attract each other.
Ionic Compounds
Cations and anions arrange themselves in
a “crystal lattice.”
![Page 20: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/20.jpg)
LPChem1415
Ionic Crystals
A “crystal lattice”Is a 3-D grid of ions– the
general structure of ionic compounds
Is hard to melt
due to attraction
between anions
and cations
![Page 21: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/21.jpg)
LPChem1415
C. Ionic Nomenclature
Ionic Names: Cations
Write the name of the cation first.
Stock System: Use Roman numerals to show the cation’s charge if more than one is possible.
D-block (transition metals)
Poor metals
![Page 22: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/22.jpg)
LPChem1415
C. Ionic Nomenclature
How do you know the Roman numeral? Math! (The overall charge must equal zero.)
oFeCl2 • Cl gets a charge of: 1- (because it is in column 17)
• Fe must have a charge of ____ to make the compound = 0
2+ oThis is Iron (II)
Chloride
![Page 23: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/23.jpg)
LPChem1415
C. Ionic Nomenclature
Fe2 S3
There are only two capital letters, so no polyatomic ion to worry about.
I look up S on the periodic table
oColumn 16:
o6 valence electrons, 2- charge
S
![Page 24: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/24.jpg)
LPChem1415
C. Ionic Nomenclature
Fe2 S3 = iron ( ? ) sulfide
Fe2 S3
2-
6-
( ) 3
= 06+
( )2 +3+
Iron (III) sulfide
![Page 25: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/25.jpg)
LPChem1415
C. Ionic Nomenclature
Fe2 (CO3)3 = iron ( ? ) carbonate
Fe2 (CO3)3 2-
6-
( ) 3
= 06+
( )2 +3+
Iron (III) carbonate
![Page 26: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/26.jpg)
LPChem1415
C. Ionic Nomenclature
Fe CO3 = iron ( ? ) carbonate
Fe CO3 2-
2-
( ) 1
= 02+
( )1 +2+
Iron (II) carbonate
![Page 27: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/27.jpg)
LPChem1415
C. Ionic Nomenclature
Ni2 CO3 = nickel ( ? ) carbonate
Ni2 CO3 2-
2-
( ) 1
= 02+
( )2 +1+
Nickel (I) carbonate
![Page 28: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/28.jpg)
LPChem1415
C. Ionic Nomenclature
Ionic Names: Cations
Roman numerals are NOT needed for:
Group 1 & 2
o(1+, 2+)
Ag, Zn, Al
![Page 29: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/29.jpg)
LPChem1415
C. Ionic Nomenclature
Monatomic anion names are the first syllable of the element name, then -ide.
(Chloride, oxide, phosphide, nitride, etc)
Polyatomic ions have special names. (Chart on the back of your periodic table.)
Do NOT change the ending of polyatomic ions.
Ionic Names: Anions
![Page 30: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/30.jpg)
LPChem1415
C. Ionic Nomenclature
Consider the following:Does it contain a polyatomic ion?o2 elements no; ending is “-ide”o3+ elements yes; ending is -ate -ite
Does it contain a Roman numeral?oCheck the table: is the metal NOT in Groups 1 or 2 (or Ag, Zn, Al)?
NO numerical prefixes!
Overview:
![Page 31: Elements and Ionic Compounds Unit II: Intro to Formulas LPChem1415.](https://reader035.fdocuments.in/reader035/viewer/2022062422/56649e7f5503460f94b8303d/html5/thumbnails/31.jpg)
LPChem1415
C. Ionic Nomenclature
NaBr
Na2CO3
FeCl3
sodium bromide
sodium carbonate
iron(III) chloride