1.3 Bonding Flashcards
True or false: state changes can change the chemical properties of a substance
False - changes in state are physical changes
What is ionic bonding?
When an atom transfers e- to form ions (between metals and non-metals)
What is an example of ionic bonding?
Sodium chloride (NaCl)
What is the difference between an anion and a cation?
Anions are negatively charged while cations are positively charged
What is electrostatic attraction?
The attraction between anions and cations
What is a covalent bond?
When 2 non-metals share e- to gain full outer shells
What is an example of covalent bonding?
Hydrochloric acid (HCl)
What is a dative coordinate bond and what is an example?
A covalent bond in which both e- come from the same atom (e.g. NH4+)
What is metallic bonding?
When metal atoms are attracted to the sea of delocalised e-
What is an example of metallic bonding?
Copper (Cu)
What are properties of ionic compounds?
- High melting + boiling points
- Can conduct electricity only when molten/in solution
- Soluble in water
- Hard + brittle
- Solid at room temp.
What are properties of metallic compounds?
- Moderately high melting + boiling points
- Can conduct electricity when solid or liquid
- Insoluble in water
- Hard + malleable
- Solid at room temp.
What are properties of simple covalent compounds?
- Low melting + boiling points
- Can’t conduct electricity
- Insoluble in water unless polar
- Soft
What are properties of giant covalent compounds?
- Very high melting + boiling points
- Graphite can conduct electricity, diamond + silicon oxide cannot
- Insoluble in water
- Graphite is soft, diamond + silicon oxide are hard
- Solid at room temp.
What is valence shell electron pair repulsion theory (VSEPR)?
The model that predicts the shape + bond angles of molecules
What are the different shapes + bond angles?
- Linear, 180°
- Bent, 104.5°
- Trigonal planar, 120°
- Trigonal pyramidal, 107°
- Tetrahedral, 109.5°
- Trigonal bipyramidal, 120°+ 90°
- Octahedral, 90°
What is electronegativity?
The power of an atom to attract the pair of e- in a covalent bond towards itself
What are the factors affecting electronegativity?
- Increased nuclear charge increases electronegativity
- Increased atomic radius decreases electronegativity
- Increases shielding decreases electronegativity
What are intramolecular forces?
The forces within a molecule
What is a non-polar bond?
When atoms in a covalent bond have the same electronegativity so the e- distribution is equal
What is a polar bond?
When the atoms in a covalent bond have different electronegativities so the e- distribution is unsymmetrical
What are Van Der Waals forces?
Temporary induced dipole-dipole attraction due to random e- movement
What are permanent dipole- dipole forces?
The forces between dipoles in polar bond molecules
What is hydrogen bonding?
A permanent dipole-dipole force in which a hydrogen is bonded to a lone pair of O, F or N
What is the strongest + weakest type of IMF?
- Strongest = hydrogen bond
- Weakest = VDWs
