u3: structure and properties of solids Flashcards
1
Q
physical properties of a solid depend on
A
- component elements
- attractive forces present (IMFs)
2
Q
types of solids
A
- ionic solid
- metallic solid
- molecular solid
- covalent network
3
Q
ionic solid definition
A
- metal and nonmetal
- pos nd neg ion attracted w electrostatic forces
4
Q
metallic solid definition
A
- two metals
- atoms
5
Q
molecular solid
A
- two nonmetals
- atoms or molecules
6
Q
covalent network
A
- metalloids (B, Si, Ge, As, Sb, Te, Po)/carbon
- atoms connected by covalent bonds
7
Q
ionic crystals
A
- pure ionic compounds in solid form are 3D crystals
- anions nd cations attracted tgthr in crystal lattice
- each anion surrounded by cations nd vice-versa
8
Q
crystal lattice
A
- regular repeating pattern of ions or molecules in a crystal
- exists in 3 dimensions
- ionic substance held by strong electrostatic attraction in all directions
- directional bonds
9
Q
physical properties of ionic compounds
A
- hard, brittle, crystalline solids
- high melting and boiling pt (high IMFs)
- don’t conduct electricity as solid, only when molten/aqueous
- soluble in water
10
Q
metallic crystals
A
- closely packed lattice
- low ionization energies + low energy unfilled orbitals
- valence elecrons become delocalized (shared by all atoms)
- “electron sea model” bc electrons free to move
11
Q
metallic bonding
A
- atoms lose valence electrons = cations
- cations attracted to free electrons = glue
12
Q
ductility and malleability of metals? alloys?
A
- attrn not between cations, but cations and mobile electrons: so ions can slide past each other w/o breaking bonds = ductile+malleable
- alloys: pure metal mixed w/ diff metals = harder to slide = harder than pure metals
13
Q
conducting properties of metals
A
- bc delocalized electrons free to move = good heat nd electricity conductors
14
Q
wht does metal bond strength depend on?
A
- number of electrons atoms share: more electrons = more hold
- how far from nucleus sea of electrons is
15
Q
how can u figure out melting point based on periodic table
A
going down a group = lower melting point