2024Chem. Unit 6 Test

crystalline × amorphous ; brittle × malleable

bond types:

• metallic:

  • metal + metal

• ionic:

  • metal + nonmetal

  • non - directional // moving away from the center of an ion, forces are equally strong in all directions

  • high melting and boiling points

  • most are crystalline solids at room temperature (crystal lattice)

  • not malleable // will shatter, hard, brittle

  • will only conduct electricity when melted or dissolved in water (aka electrolyte) ((CANNOT be solid))

  • electronegativity difference of >1.7

  • electrons are transferred !!

• covalent:

  • nonmetal + nonmetal

  • usually liquid or gas

  • low boiling point

  • electrons are shared !!

coulomb’s law…

• larger ionic radius = smaller lattice energy

• larger charge magnitude = greater lattice energy

• trends :

  • increases left to right

  • increases bottom to top

  • top right has most lattice energy
    

electronegativity : closer to fluorine = more en

enthalpy (kinda)

• takes energy to break (bonds) ; frees energy to form (bonds)

• endothermic : energy goes in

• exothermic : energy is released

ionic lewis structures…

• rules:

  • 1. charges shown on ALL ions

  • 2. cations lose electrons, anions gain electrons

  • 3. cations show no VE’s, anions show all VE’s

  • 4. when there is more than 2 tom of an element, use coefficients in lewis structure

  • 5. all ion charges should cancel out

  • 6. put brackets around full valence anion

why atoms form bonds!

• to have a valence shell that is isoelectronic to the nearest noble gas

• to lower each individual atom’s potential energy

rat boy vs cat

• …ᘛ⁐̤ᕐᐷ🏹🗡/ᐠ｡ꞈ｡ᐟ\