6.1 Ionic Bonding. Stable Electron Configurations When the highest occupied energy level of an atom...
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Transcript of 6.1 Ionic Bonding. Stable Electron Configurations When the highest occupied energy level of an atom...
Stable Electron Configurations
• When the highest occupied energy level of an atom is filled with electrons, the atom is stable and not likely to react.
• Noble gases have stable configurations with full valence electrons.
• The chemical properties depend on the valence electrons.
• Lewis created a model of showing the valence electrons– Called the Electron dot diagram, or also the Lewis Dot Structure.– Nitrogen, Group 5A
Ionic Bonds
• Elements that do not have complete sets of valence electrons tend to react.
• Some elements achieve stable electron configurations through the transfer of electrons between atoms.
Formation of Ions
• In a neutral atom the number of protons is equal to the number of electrons.
• When an Ion is formed, the number of electrons is not equal to the protons.– It has an unbalanced charge called an ion.
Examples
• Chlorine has 17 electrons normally.• – When it gains an electron it has 18, called an
ION• It now has a charge of 1-.• Written as Cl1-
• Negative Ions take the suffix “ide” in general.• Chlorines Ion is Chloride
• Sodium ions have 11 protons and 10 electrons.
• One more proton than electron means it has a 1+ charge.
• Can be written as Na1+
• When a cation and an anion are close together a chemical bond forms.
• The type of chemical bond is an IONIC BOND.
Ionization Energy
• The amount of energy needed for an electron to move to a higher energy level.– Allows e- to overcome attraction of nucleus.– Takes more energy to remove e- from a nonmetal than a metal– Decreases down a group, increases across a period.
Drawing Ionic Compounds
Draw an example of this….. Magnesium Chloride.
• 1. Draw electrons (dots)• 2. Move e- to most stable configuration• 3. Draw arrows to show new location• 4. Write the new charge of the ions formed