CP NT Ch. 7 & 9—Ionic Bonds & Compounds plus Naming
Forming Chemical Bonds
Compounds (Review)
•Remember compounds are ______or more different elements that combine chemically
•Can be broken down by ______means
•Have properties ______from those of its component element
•Thousands of compounds exist
Chemical Bonds
•A chemical bond is a force that holds ______atoms together
•
Chemical bonds usually only involve ______electrons
Valence Electrons
•Valence electrons are electrons in the ______occupied s and p energy level.
•The number of valence electrons largely ______the chemical properties of an element.
•To find the number of valence electrons in a representative (group A) element, simply look at its ______number.
Lewis dot diagram
- Diagrams that show valence electrons as dots
Why do elements react?
•Noble Gases are chemically stable because they have ______valence electrons called an octet
•Elements tend to react in order to ______a full octet or “eight is great” (gain stability)
•Octet rule –when forming compounds, atoms tend to achieve the stable electron structure of a ______
•YouTube Video: Brainiac Alkali Metals
Formation of Positive Ions-Cations
•A cation is an atom or group of atoms with a positive charge because of a ______of electrons. Ca “+” ion
•______valence electrons
•______only form cations
•Reactivity of metals is based on the ease in which they ______a valence electron to achieve a stable octet.
Electron Configuration of Positive Ions-Cations
•A sodium metal ion has the electron configuration of the noble gas neon; Ne: 8 is great!
Na atom / Na / 1s22s22p63s1Na ion (lost 1 electron) / Na+ / 1s22s22p6
Ne atom (noble gas) / Ne / 1s22s22p6
Cation Charges
•Group 1A loses 1 electron, making a _____ ion
•Group 2A loses 2 electrons, making a ______ion
•Group 3A loses 3 electrons, making a ______ion
Formation of Negative Ions-Anions
•An anion is a negative atom or group of atoms that ______electrons
•______tend to gain electrons
Electron Configuration of Negative Ions-”Anions”
•Cl ion has the noble gas configuration of argon. 8 is great!
Cl atom / Cl / 1s22s22p63s23p5Cl ion (gain 1 electron) / Cl- / 1s22s22p63s23p6
Ar atom / Ar / 1s22s22p63s23p6
Anion Charges
•5A tend to gain 3 electrons, making a ______ion
•6A tend to gain 2 electrons, making a ______ion
•7A tend to gain 1 electron, making a ______ion
•The ion produced when atoms of halogens (group 7A) gain electrons are called ______ions
Formation and Nature of Ionic Bonds
Ionic Bond
•Ionic bond – the ______force that holds ions together in an ionic compound
•______force – like charges repel, opposite charges attract
Formation of an Ionic Bond
1. Electrons are ______from a metal to a nonmetal
2. The transfer produces a cation and ______.
3. Ions are held together by ______
4. Results in a very ______crystal lattice structure.
Ionic Compounds
•Compound ______of cations and anions
•Usually a metal and nonmetal
•Overall ______charge (zero)
•Held together by ______bonds
•A.K.A.: ______
Binary Compounds
•Has just ______different elements
•A metallic cation combines with a nonmetallic anion
•Example
•-MgO
•-Not CaSO4, why?
Formula Units
•A chemical formula shows the kinds and numbers of atoms in the ______representative unit of a substance
•Sodium chloride NaCl
•A formula unit is the lowest whole-number ______of ions in an ionic compound
Example 1
Atoms / Cation / Anion / Ratio / Formula UnitMg and O / Mg / O
Na and O / Na / O
Example 2
- Predict the compound formed when magnesium and nitrogen combine.
- Start with the atoms
- Write their ions
- Crisscross charges to get neutral compound
- Write formula unit (make sure to reduce to lowest whole number ratio)
Properties of Ionic Compounds
•Strong bonds
•______melting and boiling points
•______at room temperature
•Hard, rigid, and ______
•When dissolved in water or melted it can conduct an ______current
Electrolyte
•Definition: A substance that conducts an electric current when it is ______in water.
•When an ionic compound dissolves in solution it breaks up into its ______ions. This enables it to conduct a current because the ions move around.
•Gatorade has electrolytes. It has ______dissolved in water for your body to conduct electrical currents.
Crystal Lattice
•______of ionic compounds
•Repeating ______pattern
•Large ______forces result in a very stable structure
Names and Formulas for Ionic Compounds
Types of ions
•______ion
ion with ______atom
•Mg2+ magnesium ion
•Cl-chloride ion
•______ion
ion with ______than one atom
•NH4+ammonium
•NO3- nitrate
Naming Ca””ions
•Monatomic cation name ______the same
Sodium, Na goes to ______ion, Na+
Calcium, Ca goes to ______ion, Ca 2+
•Polyatomic cation - look up in chart
NH4+ammonium
Naming Anions
•The name ______in a monatomic anion
•The ending for a monatomic anion is ______ide
(like a bride changes her last name)
–chlorine, Cl goes to ______ion, Cl-
–Fluorine, F goes to ______ion, F-
•Polyatomic anion look up in chart
–OH-hydroxide
–SO42-sulfate
Question Time
Given the neutral atom, give the charge and name of the monatomic ion that will form. (Look at periodic table group numbers for help.) For polyatomic ions (6-10, look up in chart).
- Na 6. NH4+
- Cl 7. OH-
- Mg 8. SO32-
- S 9. SO42-
- P 10. CN-
Naming ionic compounds
•Name the cation first and then the anion second (+ then -)
•Example: CsF
–Monatomic cations use the element name
–Cs+ = ______ion
–Monatomic anions – change the ending to ide
–F -=______ion
•Name: ______
Will these form an Ionic Compound? If so what will the compoundname be?
- Mg, Al
- Al, S
- Mg, O
- Na, N
- C, S
Formula Unit
•Formula Unit—the ______ratio of ions in an ionic compound
•NaCl versus Na2Cl2
•Correct: Sodium Chloride NaCl
What will the formula be?
•In ionic compounds, we must ______charges to form a ______compound.
•To do that, we “crisscross the charges” similar to finding the least common denominator in a fraction.
•Ex: Ca and N form Ca2+ and N3- ions Ca3N2
Formula Unit with Polyatomic ions
•Sometimes you will need to use ______than one polyatomic ion to balance a charge.
•If so, you need to put it in ______(like a package) and use a subscript for the multiple number
•Ex: Mg2+and NO3-
Transition Metal Ions
•Metals form ______
•Some transition metals only have ______ionic charge
•Ex: Silver (Ag+), Cadmium (Cd2+), Zinc (Zn2+)
•Some transition metals can take on ______than one charge.
•Ex: Copper (Cu+, Cu2+)
•Charge is determined from the number of electrons ______
Naming Transition Metal Ions
•If a transition metal has more than one charge, the charge is written as a ______numeral in parenthesis
•Some metals need a middle name
•Fe (iron) has more than one charge: 2+ and 3+
Fe2+______
Fe3+______
•If the transition metal only has one charge, no ______numeral is needed
Naming Ionic Compounds with Transition Metals
•Given: Fe2O3
First find the ______of the ions
Then ______the cation followed by the anion
Name: ______
Try this one: Fe3P2
Question Time
•Name the charge on the transition metal:
- Copper(II) nitrate
- Gold(I) chromate
•Name the compound:
- FeO
- Zn(OH)2
- CoPO4
Metallic Bonds and Properties of Metals
Metals
•Metals are made up of closely packed ______surrounded by electrons, rather than neutral atoms of ions
•Outer ______clouds of the metal ions overlap
•Electron sea model – metal atoms in a solid contribute their ______electrons to form a “sea of electrons”
•
Delocalized electrons – Electrons that are free to ______in the “sea of electrons”
Metallic Bond
•Definition: The ______of the delocalized electrons for the positively charged metal ions
•Metal bonded to ______
•Each ion is bonded to all ______cations by the “sea” of valence electrons
Properties of Metals
•In general, metals have moderately ______melting and boiling points
•______conductors of heat and electricity
•Electrons are free to move so transfer electrical charge/heat
•Malleable and Ductile
•Mobile electrons can easily be ______or ______past each other
Structure of Metals
•Metal atoms are arranged in very compact and orderly ______
•Metals that contain just one kind of atom are among the simplest forms of all ______solids
Metal Alloys
•Alloy is a mixture of ______or more elements (at least one must be a metal)
•Alloy’s have metallic properties often ______to those of their component
elements
Bronze: copper + tin
Steel: iron + carbon + other metals
Sterling silver: silver + copper
1