ions!
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IONS!. How they are formed. Valence Electrons. Valence Electrons of an atom are the electrons that are in the outermost s and p sub shells. (ONLY S AND P) To determine how many electrons are in your valence shell, look at where your element is on the periodic table. Valence Electrons. - PowerPoint PPT PresentationTRANSCRIPT
IONS!How they are formed
Valence ElectronsValence Electrons of an atom are the
electrons that are in the outermost s and p sub shells. (ONLY S AND P)
To determine how many electrons are in your valence shell, look at where your element is on the periodic table.
Valence ElectronsEx. Sodium- Na- In the s-block. Only 1
electron in the outermost s sub shell.You can look at the electron configuration to
help as well1s22s22p63s1- The 3s sub shell is the
outermost shell. It only has 1 electron in it. There fore it only has 1 valence electron
Valence ElectronsLets look at something that lies in the p sub
shell.Sulfur- S - 1s22s22p63s23p4- Remember
valence electrons are in both the outermost s and p sub shells
How many Valence electrons?
Lets look at Bromine. How many valence electrons does it have?
Valence ElectronsHint- Column 1 will always have 1 valence
electronColumn 2 will always have 2 valence
electronsColumn 13 will always have 3 valence
electronsColumn 14 will always have 4 valence
electronsColumn 15 will always have 5 valence
electronsColumn 16 will always have 6 valence
electronsColumn 17 will always have 7 valence
electronsColumn 18 will always have 8 valence
electrons
Valence ElectronsHow many Valence electrons do the following
elements have?Calcium – CaCesium – CsIodine – IKrypton – KrCarbon – CPolonium – Po
Lewis Dot diagramsLewis Dot Diagrams, or Electron dot
structures, are diagrams that show valence electrons as dots
Lewis Dot DiagramsPractice: How many Valence Electrons and
LDDCalcium Ca-
Cesium Cs –
Krypton Kr –
Polonium Po-
Octet RuleNotice how Krypton ( a Noble Gas) Has filled
up its valence electrons. This is why Noble Gases do not form ions or bond with anything. They are perfectly content with being filled all the way.
All the other elements are jealous and want to be like the Noble Gases, so they have to take on or lose electrons to take on this filled Valence Shell
Octet Rule states- Atoms react by gaining or losing electrons so as to acquire the stable elecron structure of a noble gas, usually eight electrons.
Cations and AnionsTo become more like the noble gases, all the
other elements will start to either gain or get rid of electrons to fill out a Valence Shell
Whether an element gains electrons or loses them depends on where it is on the periodic table and what kind of material it is
AnionsAnions are formed by non-metals (to the right
of the metalloids)Anions will gain electrons to become
negatively charged ionsBecause Noble Gases already have a full
valence shell, you will not find them becoming ions of any sort
AnionsNitrogen- forms a -3 chargeOxygen – forms a -2 chargeSulfur – forms a -2 chargeFluorine – forms a -1 chargeChlorine – forms a -1 chargeBromine – Forms a -1 chargeIodine – Forms a -1 charge
CationsCations are metals. The metals typically only
have just the s sub shell filled in the valence shell. It is easier to lose electrons to become more like a Noble Gas then to gain them
Cations will lose electrons and then therefore become positively charged.
CationsColumn 1 will lose 1 Valence electron and
form a +1 charge(Hydrogen can both lose and gain 1 electron
depending on what situation it is in)Column 2 will lose 2 valence electrons and
form a +2 charge
PracticeWhat Charge does each Element Make?Sr
Al
P
Cl
Kr
Transition Metals (D-block)The transition metals make multiple positive
ions.The way that you will be able decide what
charge that transition metal is will be determined by either having the name written out or by looking at the chemical formula of the compound that it will make
When Given the Written NameWhen you are given the written name of a
chemical formula with a transition metal in it, it will give you a roman numeral in parenthesis. The Roman numeral is the charge that the transition metal will take
Remember that Transition metals are all going to form positive ions or cations.
Ex. Iron (II) Chloride- Fe2+ reacting with Cl 1-
When Given the Chemical FormulaWhen you are given a chemical formula with
a transition element in it, Determine the charge of the anion first ( Anions do not change their charge in Ionic compounds) Then give the charge to the Transition metal that will negate the negative charge
Ex. FeCl3 – Chlorine has a charge of -1. There are three chlorines. That gives a total charge of -3. To make this a neutral atom, you must have a +3 charge to balance that out. Fe (iron) must have a +3 charge.
PracticeGive me the charge of the transition elementLead (IV) Bromide
Copper (I) Fluoride
ZnO
Ni2O3
Poly Atomic IonsPoly atomic ions are those that are formed by
more than one type of element. Can be 2 or more different elements (usually not more than 3)
Example – Nitrate Ion is NO3-
Notice that there are two different elements, Nitrogen and Oxygen
Common PolyatomicsHydroxide – OH1-
Hypochlorite – ClO1-
Nitrate – NO31-
Acetate - C2H3O21-
Bicarbonate – HCO31-
Sulfate – SO42-
Carbonate – CO32-
Phospate – PO43-
Ammonium – NH41+