A-LEVEL Chemistry: 3.1.3: Bonding (ChemRevise) Flashcards
What is ‘Ionic Bonding’?
Ionic Bonding is the Electrostatic Force of Attraction between Oppositely Charged Ions, Formed by the Transfer of Electrons.
Metal Atoms ___ Electrons to Form ___ Ions.
Lose, Positive.
Non-Metal Atoms ___ Electrons to Form ___ Ions.
Gain, Negative.
Mg has 12 Electrons. State the Electron Configuration before & after becoming an Ion. (2)
-Before: 1s2 2s2 2p6 3s2
-After: 1s2 2s2 2p6
Ionic Crystals have the Structure of…
Giant Lattices of Ions.
When are Ionic Bonds Stronger, and have Higher Melting Points?
When the Ions are Smaller, or when the Ions have Higher Charges.
MgO has a Higher Melting Point that NaCL. Why is this?
Because the Ions Involved in MgO are Smaller & have Higher Charges than those in NaCL.
Positive Ions are ___ Compared to their Atoms. Why?
Smaller. Because the Ion has One Less Electron Shell, & the Ratio of Protons to Electrons has Increased, so there is Greater Nuclear Charge on the Remaining Electrons, Pulling them in Closer.
The Negative Ions Formed from Groups 5-7 are ___ than their Corresponding Atoms. Why?
Larger. Because the Negative Ion has More Electrons than the Corresponding Atom, but has the Same Number of Protons. Hence, the Pull of the Nucleus is Shared over More Electrons, & so the Attraction per Electron is Less, making the Ion Bigger.
As you go Down a Group, the Ionic Radius ___. Why?
Increase. Because as you go Down the Group, the Ions have More Shells of Electrons.
What is a ‘Covalent Bond’?
A Covalent Bond is a Shared Pair of Electrons.
When does a ‘Dative Covalent Bond’ Form?
A Dative Covalent Bond Forms when the Shared Pair of Electrons in the Covalent Bond comes from only One of the Bonding Atoms.
Common Examples of Dative Covalent Bonds: (3)
- NH4+
-H3O+
-NH3BF3
When Representing the Structure of Dative Covalent Bonds, what does the Direction of the Arrow Represent?
The Direction of the Arrow goes from the Atom that is Providing the Lone Pair to the other Atom.
What is ‘Metallic Bonding’?
Metallic Bonding is the Electrostatic Force of Attraction Between the Positive Metal Ions & the Delocalised Electrons.
The 3 Main Factors that Affect the Strength of Metallic Bonding: (3)
-Number of Protons / Strength of Nuclear Attraction.
-Number of Delocalised Electrons per Atom.
-Size of Ion.
State the Structure for Ionic Bonds:
Giant Ionic Lattice.
State the Structures for Covalent Bonds: (2)
-Simple Molecular (with Intermolecular Forces between Molecules).
-Macromolecular (Giant Molecular Structures).
State the Structure for Metallic Bonds:
Giant Metallic Lattice.
Explain the Property ‘Boiling & Melting Points’ for Giant Ionic Lattice Structures:
High MP & BP:
Because of Giant Lattice of Ions with Strong Electrostatic Forces Between Oppositely Charged Ions.
Explain the Property ‘Boiling & Melting Points’ for Simple Molecular Structures:
Low MP & BP:
Because of Weak Intermolecular Forces Between Molecules (Specify Type eg Van Der Walls / Hydrogen Bond).
Explain the Property ‘Boiling & Melting Points’ for Macromolecular / Giant Molecular Structures:
High MP & BP:
Because of Many Strong Covalent Bonds in Macromolecular Structures. It takes a Lot of Energy to Break the Many Strong Bonds.
Explain the Property ‘Boiling & Melting Points’ for Giant Metallic Lattice Structures:
High MP & BP:
Because of the Strong Electrostatic Forces Between Positive Ions & the Cloud of Delocalised Electrons.
Describe the Property ‘Solubility in Water’ for Giant Ionic Lattice Structure:
Generally Good.
Describe the Property ‘Solubility in Water’ for Simple Molecular Structures:
Generally Poor.
Describe the Property ‘Solubility in Water’ for Macromolecular / Giant Molecular Structures:
Insoluble.
Describe the Property ‘Solubility in Water’ for Giant Metallic Lattice Structures:
Insoluble.
Explain the Property ‘Conductivity when Solid’ for Giant Ionic Lattice Structures:
Poor:
Because Ions can’t Move- they’re Fixed in the Lattice Structure due to the Electrostatic Forces of Attraction.
Explain the Property ‘Conductivity when Solid’ for Simple Molecular Structures:
Poor:
Because there are No Ions to Conduct, & there are No Free Electrons to Conduct (all Fixed in Place).
Explain the Property ‘Conductivity when Solid’ for Macromolecular / Giant Molecular Structures: (2)
-Diamond & Sand: Poor:
Because Electrons are Fixed in Place.
-Graphite: Good:
Because there are Many Delocalised Electrons Between Layers, Free to Move & Carry Charge.
Explain the Property ‘Conductivity when Solid’ for Giant Metallic Lattice Structures:
Good:
Cloud of Delocalised Electrons Can Move Freely Through the Structure, & Carry Charge.
Describe the Property ‘Conductivity when Molten’ for Giant Ionic Lattice Structures:
Good: Ions can Move.
Describe the Property ‘Conductivity when Molten’ for Simple Molecular Structures:
Poor: No Ions to Move.
Describe the Property ‘Conductivity when Molten’ for Macromolecular / Giant Molecular Structures:
Poor.
Describe the Property ‘Conductivity when Molten’ for Giant Metallic Lattice Structures:
Good.
State the Number of Bonding Pairs & Number of Lone Pairs for the Molecule Shape: ‘Linear’: (2)
-No. Bonding Pairs: 2
-No. Lone Pairs: 0