Chemical bonding and structure
- Bonding
- Metallic
- Ionic
- Covalent, simple and giant structure, dative
- Element: one type of atom compound: multiple elements
- Some elements are diatomic, they are made of 2 of the same atoms, still element
- Noble gases: Monatomic, colourless, least reactive
- Duet stability: When the S orbital is full and the final orbital, only He
- Octet stability: S orbital and P orbitals are full, 8 electrons
- All other elements look to gain either duet or octet stability with either an ionic(losing or
gaining) or covalent(sharing e-) bond
- First 5 elements in the periodic table prefer to achieve duet stability rather than octet stability.
Boron can lose 3 easier than gaining 5. First 5 elements want to achieve the same
configuration as He
- After Boron, the elements prefer to share electrons and gain octet stability
- Metallic Bonding
- The electrostatic attraction between lattice of positive ions and a sea of delocalised electrons
- Lattice: Arrangement in a repeating pattern, rows and columns
- Metalloid- Has characters of both non-metal and metal
- Metals properties:
- Lustrous (shiny)
- Ductile (can be pulled into a wire)
- High density (general)
- Good conductors of heat and electricity (delocalized electrons)
- Sonorous (vibrates and makes noise)
- Generally hard
- Malleable (can change shape)
- High MP and BP
- Non-metal properties
- Brittle (break easily)
- Not ductile (can not be pulled into wire)
- Not sonorous
- Low density
- Low Mp and Bp
- Generally soft
- Generally bad conductors of heat and electricity
- Exceptions:
- Graphite (carbon) can conduct electricity
- Iodine is shiny
- Some metals are soft, some non metals are hard
, - Mercury is liquid at room temperature, Mp Bp
- Alkali metals have low density
- Metallic bond
- Electrostatic attraction(between two opposite charges) between sea of delocalised electrons
and a lattice of positive ions
- Li loses one electron. Then forms a lattice of positive ions because each Li ion loses one e.
The lost e are delocalised and are free to move anywhere. Attraction between positive and
negative
-
- Metallic bonding going down in group one, becomes weaker and weaker
- Factors that affect metallic bonding
- Charge of metal ion (higher charge/ stronger)
- Number of delocalised e (more lost, higher charge, stronger
bonds)
- Ionic radius needs to be small (smaller radius, stronger pull).
This is because the electrons that need to be pulled are
getting further away from the nucleus when the atomic radius
grows
- Therefore, going down group 1, the metallic bonding becomes weaker, the elements
become softer
- Across the period, metallic bonding strength increases, because as you go across,
normally more electrons are released and the charge is higher
- Malleability: can be shaped under pressure
- Ductile: Can be pulled into a wire
- This is because there are delocalised electrons in between them in metals, the layers can then
slide over each other
- Conductivity: Metals can conduct electricity, when connecting a metal to a power source, the
delocalised electrons will flow all in one direction, allowing it to complete the circuit
- Bonding
- Metallic
- Ionic
- Covalent, simple and giant structure, dative
- Element: one type of atom compound: multiple elements
- Some elements are diatomic, they are made of 2 of the same atoms, still element
- Noble gases: Monatomic, colourless, least reactive
- Duet stability: When the S orbital is full and the final orbital, only He
- Octet stability: S orbital and P orbitals are full, 8 electrons
- All other elements look to gain either duet or octet stability with either an ionic(losing or
gaining) or covalent(sharing e-) bond
- First 5 elements in the periodic table prefer to achieve duet stability rather than octet stability.
Boron can lose 3 easier than gaining 5. First 5 elements want to achieve the same
configuration as He
- After Boron, the elements prefer to share electrons and gain octet stability
- Metallic Bonding
- The electrostatic attraction between lattice of positive ions and a sea of delocalised electrons
- Lattice: Arrangement in a repeating pattern, rows and columns
- Metalloid- Has characters of both non-metal and metal
- Metals properties:
- Lustrous (shiny)
- Ductile (can be pulled into a wire)
- High density (general)
- Good conductors of heat and electricity (delocalized electrons)
- Sonorous (vibrates and makes noise)
- Generally hard
- Malleable (can change shape)
- High MP and BP
- Non-metal properties
- Brittle (break easily)
- Not ductile (can not be pulled into wire)
- Not sonorous
- Low density
- Low Mp and Bp
- Generally soft
- Generally bad conductors of heat and electricity
- Exceptions:
- Graphite (carbon) can conduct electricity
- Iodine is shiny
- Some metals are soft, some non metals are hard
, - Mercury is liquid at room temperature, Mp Bp
- Alkali metals have low density
- Metallic bond
- Electrostatic attraction(between two opposite charges) between sea of delocalised electrons
and a lattice of positive ions
- Li loses one electron. Then forms a lattice of positive ions because each Li ion loses one e.
The lost e are delocalised and are free to move anywhere. Attraction between positive and
negative
-
- Metallic bonding going down in group one, becomes weaker and weaker
- Factors that affect metallic bonding
- Charge of metal ion (higher charge/ stronger)
- Number of delocalised e (more lost, higher charge, stronger
bonds)
- Ionic radius needs to be small (smaller radius, stronger pull).
This is because the electrons that need to be pulled are
getting further away from the nucleus when the atomic radius
grows
- Therefore, going down group 1, the metallic bonding becomes weaker, the elements
become softer
- Across the period, metallic bonding strength increases, because as you go across,
normally more electrons are released and the charge is higher
- Malleability: can be shaped under pressure
- Ductile: Can be pulled into a wire
- This is because there are delocalised electrons in between them in metals, the layers can then
slide over each other
- Conductivity: Metals can conduct electricity, when connecting a metal to a power source, the
delocalised electrons will flow all in one direction, allowing it to complete the circuit
