Ionic Bonding Chapter 6

Quick Review Atomic number = Total number of electronsAtomic number = Total number of electrons The group number tells you the amount of valence electrons an element has.The group number tells you the amount of valence electrons an element has. The metals are on the left side of the periodic tableThe metals are on the left side of the periodic table The nonmetals are on the right side of the periodic table.The nonmetals are on the right side of the periodic table. All elements need 8 electrons in their outer shell to be stable. (Except H and He, they only need 2)All elements need 8 electrons in their outer shell to be stable. (Except H and He, they only need 2)

Valence Electrons Valence Electrons Valence Electron - Any electron that is in the outermost energy level of an atom. Valence Electron - Any electron that is in the outermost energy level of an atom. When the outer most (highest) energy level is full the atom is stable. It will most likely not reactWhen the outer most (highest) energy level is full the atom is stable. It will most likely not react What family (group) is least reactive? Why?What family (group) is least reactive? Why?

How many valence electrons? List the number of valence electrons for the following elements:List the number of valence electrons for the following elements: 1. Potassium__________________1. Potassium__________________ 2. Silicon ____________________2. Silicon ____________________ 3. Oxygen____________________3. Oxygen____________________ 4. Boron______________________4. Boron______________________ 5. Helium_____________________5. Helium_____________________

Electron Dot Diagrams

Steps for drawing dot diagrams 1. Figure out the number of valence electrons by looking at the periodic table.1. Figure out the number of valence electrons by looking at the periodic table. 2. Write the element symbol2. Write the element symbol 3. Put the dots around the symbol (dots= valence electrons) * start at the top and work clockwise just like the Bohr atom models.3. Put the dots around the symbol (dots= valence electrons) * start at the top and work clockwise just like the Bohr atom models. ** Remember: each space must be filed with 1 electron before they can double up.** Remember: each space must be filed with 1 electron before they can double up.

Examples CalciumCalcium SulfurSulfur NeonNeon Remember the Rules Remember the Rules 1. Figure out the number of valence electrons by looking at the periodic table.1. Figure out the number of valence electrons by looking at the periodic table. 2. Write the element symbol2. Write the element symbol 3. Put the dots around the symbol (dots= valence electrons) * start at the top and work clockwise just like the Bohr atom models.3. Put the dots around the symbol (dots= valence electrons) * start at the top and work clockwise just like the Bohr atom models. ** Remember: each space must be filed with 1 electron before they can double up.** Remember: each space must be filed with 1 electron before they can double up.

Ion Formation

ion

Lose or gain? ElementGain or lose electrons?How many electrons need to be lost or gained? Potassium (K) Silicon (Si) Oxygen (O) Boron (B) Hydrogen (H) Carbon (C) Nitrogen (N)

H would like to C would like to N would like to O would like to Gain 4 electrons Gain 1 electron Gain 3 electrons Gain 2 electrons

Ionic Bond

How to draw an ionic bond!!!! 1. Write out the symbols for the elements you are trying to bond.1. Write out the symbols for the elements you are trying to bond. 2. Draw the Dot Diagram2. Draw the Dot Diagram 3. Determine which element is the metal and which one is the nonmetal (Which one is going to lose/gain electrons)3. Determine which element is the metal and which one is the nonmetal (Which one is going to lose/gain electrons)

Drawing ionic bonds Show the transfer of electrons using arrowsShow the transfer of electrons using arrows Na + Cl Na + Cl - Na + Cl Na + Cl -

1). Ionic bond – electron from Na is transferred to Cl, this causes a charge imbalance in each atom. The Na becomes (Na+) and the Cl becomes (Cl-), charged particles or ions.

If an atom loses electrons: It becomes a positive ion = CATIONIt becomes a positive ion = CATION These are elements that have 3 or less valence electronsThese are elements that have 3 or less valence electrons Elements that have 4 valence electrons can become cations or anions depending on the situation!Elements that have 4 valence electrons can become cations or anions depending on the situation!

If an atom gains electrons : It becomes a negative ion = ANIONIt becomes a negative ion = ANION To name an anion, change the element’s name to have “ide” at the endTo name an anion, change the element’s name to have “ide” at the end These are elements that have 5 or more valence electronsThese are elements that have 5 or more valence electrons

Formation of Ions from Metals Ionic compounds result when metals react with nonmetals Ionic compounds result when metals react with nonmetals Metals lose electrons to gain a full outer electron shell (the next electron shell becomes the new outer shell) Metals lose electrons to gain a full outer electron shell (the next electron shell becomes the new outer shell) Positive ions form when electrons are lostPositive ions form when electrons are lost Group 1A metals  ion +1 Group 2A metals  ion +2 Group 3A metals  ion +3

Formation of Ions from Nonmetals Nonmetals gain electrons to gain a full outer electron shell Nonmetals gain electrons to gain a full outer electron shell Negative ions form when electrons are gainedNegative ions form when electrons are gained Group 5A nonmetals  ion -3 Group 6A nonmetals  ion -2 Group 7A nonmetals  ion -1 Group 8A elements do not gain or lose electrons since they already have a full outer shell. Group 8A elements do not gain or lose electrons since they already have a full outer shell.

The formation of sodium chloride (salt)

Properties of Ionic Compounds 1.Individual atoms are bound tightly together forming crystal structures 2.High melting points 3.High boiling points 4.Conduct electricity when melted or in solution 5.Many can be dissolved in water