metals 3.5 Flashcards
what’s the structure of metals?
- a lattice of positive metal ions
- sea of delocalised electrons - lost by metal ions so they move freely through lattice
what’s the definition for metallic bonding?
metallic bonding is the electrostatic attraction between the positive metal ions and the negative delocalized electrons
what types of atoms are involved in metallic bonding?
metal to metal ions
what type of attraction is metallic bonding?
very strong attraction
why do metals tend to have high melting points?
as metallic bonding is very strong and lots of energy is needed to break it
why can metals conduct electricity?
as delocalised electrons are free to move through the lattice
why are metals malleable?
as the layers of metal ions can slide over each other
what’s thermal decomposition?
when heat energy is used to break down a substance
what’s the equation for metal carbonate decomposition?
metal carbonate > metal oxide + carbon dioxide
for example
copper carbonate > copper oxide + carbon dioxide
what’s the colours involved with the decomposition of metal copper carbonate?
copper carbonate (green solid) > copper oxide (black solid) + carbon dioxide (colourless gas)
what’s downwards delievery?
carbon dioxide is denser than air so it is collected in a downwards delivery
as it sinks to the bottom of the tube and stays there until you want to use it
what are the most reactive metals?
K
Na
Li
Ca
Mg
Al
what the reaction of metal and water?
metal + water > metal hydroxide + hydrogen
for example
magnesium + water > magnesium hydroxide + hydrogen
what two observations can be made about the metal + water reaction?
effervescence - due to the hydrogen gas being produced
solid disappears - due to it being used up in the reaction
what are group 1 metals called?
alkali metals
how do group 1 metals react in the metal + water reaction?
react violently with the water
metal + water > metal hydroxide + hydrogen
for example
lithium + water > lithium hydroxide + hydrogen
what’s some of the observations of the group 1 metals and water reaction?
solid floats - less dense than water
effervescence - hydrogen gas in produced
solid moves - effervescence propels it around the surface of water
solid disappears - used up in reaction
what happens if a universal indicator is added to the water after the group 1 metals + water reaction?
turns dark blue as metal hydroxides are alkalis as they donate OH-
what is metal hydroxides?
alkalis
donate OH-
what’s the reactions of Li, Na, K in the group 1 metals + water reaction?
Li - fast
Na - faster, Na melts
K - fastest, K melts, lilac flame
what’s the reactivity trend of group 1 metals?
get more reactive as you go down the group
why do group 1 metals get more reactive as you down the group?
- atoms get bigger and have more shells
- outer shell electron is further from nucleus
- attraction between nucleus and outer shell electron is weaker
- less energy is needed to break the attraction
what the metal + steam reaction?
metal + steam > metal oxide + hydrogen
for example
magnesium + water > magnesium oxide + hydrogen
how is the metal + steam reaction conducted?
in a horizontal tube with wet wool
a metal
causes H2 to become on fire
wet wool is heated to generate steam for metal to react with
H2 gas is ignited to safely destroy it