CHAPTERS 4.1-4.3 Flashcards
what is metallic bonding?
the electrostatic force of attraction between metal cations and delocalised electrons in a crystal lattice
what are some properties of metals?
- relatively high melting and boiling points
- good conductors of electricity
- good conductors of heat
- generally have high densities
why are metals lustrious?
the sea of delocalised electrons reflects light
why are metals malleable/ductile?
non-directional bonding allows layers of cations to move past one another without disrupting the force between the cations and the sea of electrons (not restricted to one bond, will not fall apart)
why are metals good conductors of electricity?
delocalised electrons flow throughout metal
why are metals good conductors of heat?
delocalised electrons gain kinetic energy and transfer it to other parts of the lattice
why do metals have high densities (high melting points are are hard)?
strong metallic bonding in the lattice requires lots of energy to disrupt. the larger the metal ion, the lower the melting point will be
why do metals react by losing electrons?
they have low ionisation energy
how do you determine the reactivity of metals?
by looking at what happens when they are exposed to water, oxygen or acids
what is an example of a metal that does not react, or reacts very little with water?
gold, copper, magnesium
what is an example of a metal that reacts with water?
sodium, potassium, rubidium, strontium
which group of elements is at the top of the reactivity series of metals?
group 1
in general, what happens to the reactivity of ‘main group metals’ in the periodic table?
down a group: increases
across a period: decreases
what does refining metals mean?
the process of removing impurities in the metal, often improves the properties (makes them less brittle)
what are some reasons recycling metals might be difficult?
- collection and sorting can be uneconomical (expensive)
- alloys require sophisticated technology for separation (steel, carbon in the alloy)
- contamination with hazardous waste
- toxic metals such as lead are too dangerous to recycle (led)
