What is Ionic Bonding?
Ionic Bond: Electrostatic attraction between oppositely charged ions.
How do metals behave in Ionic Bonding?
Metals lose outer electrons to achieve noble gas structure and form positive ions (cations).
Group 1: 1+ ions, Group 2: 2+ ions, Group 3: 3+ ions. Exceptions: Transition metals may form variable charges.
How do non-metals behave in Ionic Bonding?
Non-metals gain electrons to achieve noble gas structure and form negative ions (anions).
Group 7: 1- ions, Group 6: 2- ions, Group 5: 3- ions. Non-metal ions end in -ide (e.g., oxide, chloride).
What is required for Ionic Compound Formation?
Charges on ions must cancel out for overall neutrality.
- only show outer shells unless told otherwise
What is Covalent Bonding?
Covalent Bond: Attraction between a nucleus and a shared pair of electrons.
What are exceptions to the Octet Rule?
- BF3: Boron stable with 6 electrons; group 3 elements can make only 3 bonds.
- Expanding the octet- atoms in period 3 or higher (eg. PCl5) can hold more than 8 electrons due to 3rd shell
What are multiple covalent bonds?
Single bond: One pair of electrons shared.
Double bond: Two pairs shared (e.g., O2).
Triple bond: Three pairs shared (e.g., N2).
What are the key properties of Ionic Compounds?
- High melting and boiling points due to strong ionic bonds.
- Solid does not conduct electricity; molten/aqueous conducts as ions are free to move
- Water solubility as polar water molecules surround and seperate ions in the lattice
What is a Dative Covalent Bond?
Dative Covalent Bond: Shared pair of electrons provided by one atom, represented with an arrow from donor to acceptor atom.
What is VSEPR?
Valence Shell Electron Pair Repulsion: Electron pairs repel to maximize distance.
How do lone pairs affect bond angles?
Lone pairs reduce bond angles by 2.5° per pair due to greater repulsion.
What is Electronegativity?
Electronegativity: Ability of an atom to attract a pair of electrons in a covalent bond.
What are the trends in Electronegativity?
Increases across a period and up a group.
- Most electronegative elements: Fluorine > Oxygen > Nitrogen.
What is polarity in bonds and molecules?
- Nonpolar bond: Equal electronegativity- electrons shared equally
- Polar bond: Unequal electronegativity. dipole forms
How do you determine the polarity of a molecule?
- Symmetrical molecules are nonpolar;dipoles cancel
- asymmetrical molecules are polar.
What are the anomalous properties of water due to hydrogen bonding?
High boiling point, less dense ice structure ( due to open lattice) , and surface tension due to strong intermolecular hydrogen bonding , require more energy to break.
