Bonding and Organic Flashcards
What is metallic bonding and how is it made
Electrostatic attraction between positve cations and delocalised electrons
- Delocaliserd electrons free to move in 3-D lattice, attraction non-directional
Made through atoms losing electrons, becoming cations
- Electrons delocalise, where cations in fixed position, electrons aren’t
What is metallic bonding melting & boiling points
High melting & boiling points
Strong electrostatic attraction between cations & delocalised electrons
- More delocalised electrons = Stronger attraction
- Smaller cation = Stronger attraction
What is metallic bonding electrical conductivity
Good conductors of electricity
Delocalised electrons move towards positive electrode from negative electrode in circuit
- Number of electrons don’t change, carries current
What is metallic bonding thermal conductivity
Good conductors of heat
Heat energy picked up delocalised electrons, transferred through metal
- Energy absorbed by nucleus of cation, making it vibrate = Causes other nuclei to vibrate, conducting heat
What is metallic bonding malleability and ductility
Malleable and ductile
Force causes cations to roll over on eachother
- Layers of cations still held together by delocalised electrons between them
- Enough stress applied = Permanent change in position
- Therefore size of force required to deform bond = Large
What is ionic bonding and how is it made
Arrangement of positively & negatively charged ions in crystalline lattice (Positive & Negative)
- Strong electrostatic force of attraction between oppositely charged ions
Made through electron being transferred from metal to non-metal, so both can have full outer shell (Octet Rule)
- Anions & Cations form 3-D crystal lattice, held together by strong electrostatic forces
What is ionic bonding melting & boiling points
High melting & boiling points
Strength of electrostatic attraction between cations & anions large
- Large amount of energy needed to overcome attraction
- Larger charge of ions = Stronger attraction
- Smaller atoms = Stronger attraction
What is ionic bonding hardness & brittleness
Hard and brittle
Strength of electrostatic attraction between anions & cations large
- Strong force required to disrupt crystal lattice = Hard
When force large enough to disrupt lattice applied, brings like-charges next to eachother
- Like charges repel = Crystal shatters
What is ionic bonding electrical conductivity in ionic solids
Cannot conduct electricity
- Ions in fixed positions, cannot move
What is ionic bonding electrical conductivity in ionic solutions / molten
Can conduct electricity
Ionic compound melt, ions free to move, cations & anions in compound can conduct electricity
Ionic compound dissolved, ionic bonds broken, can move freely in solution, conducting electricity
What is covalent molecular bonding
When valence electrons are shared between atoms, so atoms have full outer shell
How is covalent molecular bonds made
Non-Metallic atoms have high number of valence electrons, tend to share rather then transfer atoms
- Molecules formed more stable then regular atoms (Full outer shell)
- Positively charged nuclei of neighbouring atoms have attraction for shared electrons, keeps atoms held together in molecule (Electrostatic attraction)
- Is direction bond, electrons aligned along axis between atoms that share electrons
What are the types of covalent bonds
Single covalent bond; Shares 1 pair of electrons (Eg. Cl2, H2)
Double covalent bonds; Shares 2 pairs of electrons (Eg. O2)
Can share up to 7 pairs of electrons
- 8th pair; Repulsive force so big, atom shatters
- One less valence electron = 1 more pair shared
What are covalent molecular bonding melting & boiling points
Low melting & boiling points
Covalent molecular solid melts/boils, breaks weak attractive forces with other molecules (Intermolecular forces)
- Requires little energy, easily overcome with low temperature
- Bonds between neutral molecules so weak, substances exist as gases or volatile liquids at room temperature
What are covalent molecular bonding electrical conductivity
Cannot conduct electricity
Electrons localised, not free to move
- Electrons shared, not transferred, so no charged ions
What are covalent molecular bonding hardness
Very soft, easily deformed, waxy appearance
Very little force required to push neutral molecules past eachother
What is covalent network bonding
Continuous array of covalently bonded atoms
- Ordered structure, can be crystal/lattice
- Large network of covalent bonds
Eg. Carbon atoms in diamond
What is covalent network bonding melting & boiling points
High melting & boiling points
Has many strong covalent bonds in a lattice which need to be broken
What is covalent network bonding electrical conductivity
Cannot conduct electricity
Electrons localised, not free to move
- Electrons shared, not transferred, so no charged ions
What is covalent network bonding hardness
Hard
In 3-D crystalline lattice, all covalent bonds held firmly in fixed position
- Strong covalent bonds between atoms (Intramolecular forces), making it hard
What are allotropes
Forms of a chemical element that exist in the same physical state (Different organisation of network)
What is diamond as an example of a carbon allotrope
Each carbon bonded to 4 other carbon atoms (Covalent network lattice)
No weak intermolecular forces, only strong covalent bonds in fixed positions (Intramolecular forces)
= Hard, non-conducting, high melting & boiling points, brittle
What is graphite as an example of a carbon allotrope
Each carbon bonded to 3 other carbon atoms, forms 2-D layers (Covalent layer lattice)
Strong covalent bonds between carbon atoms in layers, weak forces (Dispersion) between layers
= High melting & boiling points, hard in one direction but soft & slippery in another (Not brittle)
4th valence electron not bonded (Delocalised), can move through layer
= Electrical conductivity
What is fullerenes as an example of a carbon allotrope
Covalently bonded carbon in series of hexagons/pentagons, spherical/cylindrical shape
No delocalised electrons, atoms held in fixed positions, very few covalent bonds
= Soft, cannot conduct electricity, low melting point
Nanomaterial, each carbon bonded to 3 other carbons in ball or tube shape
How to name covalent molecular elements
Normal elements name