Chapter 3 Flashcards
(15 cards)
Define ionic bonding.
Electrostatic attraction between oppositely charged ions in a lattice.
Explain how ionic bonds form between metals and non-metals.
Metals lose electrons to form positive ions; non-metals gain electrons to form negative ions; opposite charges attract.
What is the structure of ionic compounds?
Giant ionic lattice with strong ionic bonds in all directions.
Why do ionic compounds have high melting and boiling points?
Strong ionic bonds require lots of energy to break.
Explain covalent bonding.
Sharing of electron pairs between atoms.
Describe the difference between a single, double, and triple covalent bond.
Single shares one pair of electrons, double shares two pairs, triple shares three pairs.
What is a dative (coordinate) bond?
A covalent bond where both electrons come from the same atom.
Explain the structure of giant covalent substances.
Network of atoms bonded covalently in a giant lattice (e.g., diamond, graphite).
Why does diamond have a very high melting point?
Each carbon atom forms four strong covalent bonds in a rigid 3D lattice.
Explain why graphite conducts electricity.
Each carbon atom forms three covalent bonds with one delocalised electron free to move.
What is the shape and bond angle of methane (CH₄)?
Tetrahedral shape with bond angle 109.5°.
What is the shape and bond angle of ammonia (NH₃)?
Trigonal pyramidal shape with bond angle 107°.
What is the shape and bond angle of water (H₂O)?
Bent shape with bond angle 104.5°.
Explain why lone pairs reduce bond angles.
Lone pairs repel more strongly than bonding pairs, pushing bonds closer together.
What is hydrogen bonding?
Strong dipole-dipole attraction between hydrogen and highly electronegative atoms (F, O, N).
