Chapter 4: Metals Flashcards
why are alkali metals different (group 1)
they are much softer and react vigorously with water
what are 3 properties of transition metals
higher tensile strength
harder
denser
some have strong magnetic properties
why are transition metals different to normal metals
atoms are smaller size due to lower core charge, therefore they can pack together tightly
why are metals hard with high BP and MP
strong electrostatic forces between electrons and protons, which holds the lattice together strongly
why are metals electrical conductors
they have delocalised electrons dispersed throughout the lattice. These electrons are able to hold a charge and transport it away from negative electrodes and towards positive electrodes in a circuit.
why are metals ductile and malleable
when a force causes layers of the lattice to shift they are able to be held together by the electrostatic attraction between the delocalised electrons and the protons which causes the bonding to be non localised and therefore not shatter
what are the periodic table trends of reactivity of metals
going left to right across a period reactivity decreases
going down a group reactivity increases
why are metals reactive compared to non metals
they have lower ionisation energies therefore there is less energy required to remove electrons from the atom
what is the difference between interstitial alloy and substitutional alloy
interstitial is with smaller atoms usually non metals that sit in interstices
substitutional is with larger atoms usually metals and some of the original metal cations are replaced with different atoms
why does work hardening work
the crystals in the metal are flattened and pushed together, strengthening it
why does heat treatment work
changes the size and arrangement of the crystals to change it’s properties
why are metal nanomaterials different to the bulk form
the quantity of atoms in the lattice is too small to form a sea of delocalised electrons, which causes different optical properties and heat sensitivity
what are the dimension restrictions for nanorods
each dimension on the nanoscale
side ratio 3:1 - 5:1
what are the dimension restrictions of nanoparticles
the diameter must be between 1-100nm
what are the dimension restrictions of nanowire
length is unrestricted but width must be on the nanoscale
