3.5 METALS Flashcards
Describe metallic structure
- Lattice of positive metal ions
- Sea of delocalised electrons
- Metal ions have their usual charges and electrons are labelled e-
Define metallic bonding
The strong electrostatic force of attraction between a lattice of positive metal ions, and a seas of delocalised electrons
Explain why metals have high melting points
- The metallic bonds are very strong
- There are lots of metallic bonds in the structure
- A lot of energy is required to break the strong metallic bonds
Explains why metals conduct electricity
The sea of delocalised electrons are free to move through the positive metal ion lattice, allowing current to flow
Explain why metals are malleable
The layers of metal ions are able to slide over each other
Define a thermal decomposition
A reaction where heat (thermal) energy is used to break down a substance
Metal carbonate thermal decomposition reaction
Metal Carbonate → Metal Oxide + Carbon Dioxide
Colour of copper carbonate
Green
Colour of copper oxide
Black
What is downward delivery
As CO2 is denser than air, carbon dioxide sinks to the bottom of a tube and stays there until it is needed
Reactivity series
- Potassium
- Sodium
- Lithium
- Calcium
- Magnesium
- Aluminium
- Carbon
- Zinc
- Iron
- Lead
- Hydrogen
- Copper
- Silver
- Gold
First 6 metals of reactivity series
- Potassium
- Sodium
- Lithium
- Calcium
- Magnesium
- Aluminium
Middle of reactivity series
- Carbon
- Zinc
- Iron
- Lead
Bottom or reactivity series reactivity series
- Hydrogen
- Copper
- Silver
- Gold
Metal and water reaction
Metal + Water → Metal hydroxide + Hydrogen
Observations to a metal and water reaction
- Effervescence - due to hydrogen gas being produced
- Solid disappears - Used up in the reaction
Observations to Alkali Metals reacting with water
- Solid floats - Less dense than water
- Effervescence - Hydrogen gas is produced
- Solid Moves - The effervescence propels it around the surface of the water
- Solid disappears - It is used up in the reaction
Unique reaction to potassium reacting with water
The potassium melts and produces a lilac flame
Unique reaction to sodium reacting with water
Sodium melts
Why do the alkali metals get more reactive down the group
- Reacts by losing its outer shell electron to gain a full shell
- The atoms get bigger and have more shells down the group
- The outer-electron is further from the attraction of the nucleus
- The attraction between the nucleus and outer-electron is weaker
- So less energy is needed to break the attraction