bonding Flashcards
substances
made of single repeating unit at atomic level
mixture
made of several repeating units at atomic level
2 properties of particles
always have kinetic energy
always hold onto each other
3 properties of metals
malleable
ductile
conductive
electron sea model
electrons in a metal can move freely around in the structure
what keeps electrons together in electron sea model
positive ions form structure and balance charge of delocalized electrons
whats a lattice
regular repeating structure of ions
what holds lattice together
electrostatic force between cation and electron
stronger attraction in cations and electrons
stronger metallic bonding
why are metals malleable
lattice shape changed but cations can slide over each other keeping shape and metallic bonding
what happens when metal turns to liquid
regular lattice structure broken and cations can slide over each other
properties of liquid metal
not malleable or ductile
shiny and conductive
bonding in a liquid metal
does have delocalized electrons
weaker metallic bonding
higher melting point of metals
stronger metallic bonding
properties of gas
no metallic bonding and higher boiling point
do metals in liquid state have lattice
no lattice of cations
what happens when a metal boils
overall attractive forces overcome repulsive forces so no balance of forces
why do metals have higher melting and boiling points
because there is a strong attraction between cations and delocalized electrons
properties of metal gases
only have metal atoms
trend of metallic bonding
increases across period
why do metallic bonding increase across period
ions in lattice become more charges and number of electrons increases so higher electrostatic force between cation and electrons
why cant metals delocalize electrons all the time
only delocalize outer shells electrons
why can metals only delocalize outer shell electrons
only largest orbital overlap
small orbitals dont overlap so cant delocalize
trend of metallic bonding down group
decreases
why does metallic bonding decrease down group
size increases so more distance between cations nucleus and electrons so weaker forces
2 features of cations that effect metallic bonding
charge and size
state and explain general properties of metals exam question
melting point across period 3 eg
charge of cation increases so stronger attraction between cations and electrons
stronger attraction means stronger metallic bonding
compare melting point of 2 metals
eg mg ions more charges than potassium ions so stronger attraction of cations and electrons
stronger bonding so more energy to break forces
explain general melting point down group
size increases so more distance between cation and electrons so less energy required
what are alloys
metals with 2 or more elements
properties of all salts
high melting and boiling points
brittle
soluble
only conductive soluble
whats the perfect ionic model
all salts are made of positive and negative ions arranged in 3D lattice and ions perfect spheres
what keeps lattice together in ionic bonding
negative and positive electrostatic force/ attraction
what is ionic bonding
attraction between all cations and anions in lattice
charge of silver
+
charge of zinc
2+
charge of iron
2+ or 3+