Chapter 3:Metals Flashcards
(29 cards)
metallurgy
science of modifying metals.
5 careers/categories metals are required.
- construction
- agriculture
- art
- medicine
- transport
3 Metal ages in order
- Copper Age (5000-3000BCE)
- Bronze Age (3000-1000BCE)
- Iron Age (from 1000 BCE)
4 Properties of metals
1) have a range of melting points and relatively high boiling points
2) are good conductors of electricity
3) are good conductors of heat
4) generally have high densities
2 Exception of the properties of metals
1) Mercury = liquid in room temp, unusually low melting point
2) Alkali Metals (group 1) = different from other metals
- soft enough to be cut by knife
- react vigorously with water to produce hydrogen gas.
5 Common metallic CHARACTERISTICS
1) malleable- can be shaped by beating or rolling
2) ductile - can be drawn into a wire
3) lustrous or reflective - when freshly cut or polished
4) are often hard with high tensile strength
5) have low ionisation energies and electronegativities
octet rule
electrons combine so there are 8 electrons in the outer shells.
are metals or non metal atoms larger in ions?
is the core charge higher in metals or non metals?
metal atoms = larger than non metallic atom
core charge= lower in metals
ionisation energies is lower in metals than for non metals in the same period
what are cations?
- POSITIVE IONS
- lose electrons in valence shells
how to determine the charge
1) determine the number of protons and electrons in atom
2) figure out the shell configuration
3) amount of electrons - number of valence electrons
4) Cation charge = number of protons - number of electrons (without the valence electons)
5 points about Transition metals
- between group 2-13
- known as d-block
- have unfilled d-subshells
- are usually silver coloured and similar in appearance
- transition metal compounds tend to be brightly coloured
4 Properties of transition metals
1) they tend to be harder
2) they have higher densities
3) they have higher melting points
4) some have strong magnetic properties
why are transition metals hard , have higher densities and higher melting points?
- atoms of transition metals are smaller in size due to their greater core charge
- this allows them to pack together tightly with stronger bonds.
metals are usually hard and then to have high melting points. What does this tell us about it’s structure.
the forces between the particles must be strong
Metals conduct electricity in the solid and molten liquid state. What does this tell us about it’s structure?
metals have charged particles that are free to move
Metals are malleable and ductile
What does this tell us about it’s structure.
the attractive forces between the particles must be stronger than the repulsive forces between the particles when the layers of particles are moved
metals generally have high densities
What does this tell us about it’s structure.
the particles are closely packed in a metal
metals are good conductors of heat
What does this tell us about it’s structure.
there must be a way of quickly transferring energy through a metal object
Metals are lustrous or reflective
What does this tell us about it’s structure.
free electrons are present, so metals can reflect light and appear shiny
metals tend to react by losing electrons
What does this tell us about it’s structure.
electrons must be relatively easily removed from metal atoms
3 things metal bonding model must include
1) charged particles that are free to move and conduct electricity
2) strong forces of attraction between atoms throughout the metal structure
3) some electrons that are relatively easily removed.
lattice
tightly packed arrangement
delocalised
spread throughout a large area.
- in the metallic bonding model positive metal cations are surrounded by a sea of delocalised electrons
metals are hard and have relatively high boiling points
explanation?
strong electrostatic forces of attraction between positive metal ions and the sea of delocalised electrons holds the metallic lattice together
