Metallic properties and bonding Flashcards
where are metals found
in the earths crust in the form of ores ( rock or deposits that contain metals and other minerals)
chemical properties of metals (boonding)
large atomic radius, low electronegativity, low first ionisation energy, easy tpp remove valence electrons, forms positively charged ions (cations)
what structure are metals in
metals ccan bond with other atoms of the same type to form a crystal lattice structure formed of metal cations strongly held together in fixed positions and a sea of delocalised (valence) electrpms around them
what holds the metals together
the electrostatic attraction between the delocalised electrons and cations
alloys
mixture of different metals, usually metals that are mixed with small amounts of another metal or carbon (atoms of different metals do not bond together)
why is metallic bonding non-directional/free-flowing
the electrostatic forces of attraction between the delocalised electrons and cations are in all directions, unlike covalent and ionic bonding which are directional forces
physical properties of metals
large atomic radius, malleable, ductile, heat conductivity, electrical conductivity, high melting point, high bioling point and lusturuos, high densities
malleablE
ability for changes to be made in its shape via being bent or hammered, without breaking
ductile
ability for metal to be drawn into a thin wire
how come metals are malleable and ductile
tthe mechaincal force resulting in the layers of cations sliding over one another while still being held in place by the electrostatic attraction. the attractive forces between the particles are stronger than the repulsive forces betwween the particles when the layers are moved
what causes metals to conduct electricity
when connected to a circuit, electrons can move from the negative electrode to the positive electrode, the movement of the delocalised electrons can carry an electrical current
what makes metals have a high melting/boiling point and heat/electricity conductor
when a piece of metal absorbs heat, the rise in temp will result in an increase in kinetic of the cations and electrons, the delocalised electrons will transfer kinetic energy from the hotter regions to the colder regions
why are metals lusturous
The delocalised electrons can move freely in the metal causing light n on them to get reflected back. This is reflected rather than diffused and thus the metal surface appears shiny or lustrous .
what metals are different from most other metals
group 1, alkali metals
what makes alkali group 1 metals different from other metals
they are soft enough to be cut with a knife, other metals are often hard with a high tensile strenth and they all react vigoursly with wwater to produce hydrogen gas
tensile strenth
a measure of the force needed to break something or cause it to fail, such as a cable or peice of metal in the wing of a plane
what do alloys differ from pure metals physically
they are usually harder and have a lower melting point
which metal is one of few used in its pure form
copper
why do metals have a high density
the particless are closley packed in
what is the metallic bonding model
a model that has been developed to describe the arrangment of particles within a single metal crystal
what is required for the matllic bonding model to be valid
charged particles that are free to move and conduct electricity, strong forces of attraction between particles throughout the metal structure, some elctrons that are relatively easily removed
crystal
a region in a solid where the particles are arranged in a regular way
lattice
tightly packed regular arrangement
what does thhe metallic bonding model not explain
the range of melting points, hardness and densities between different metals, differences in electrical conductivities, the magnetic nature of some metals
