Metals Flashcards
What are the two components of the structure of a metal?
A lattice of positive metal ions and a sea of delocalised electrons
What is metallic bonding?
The electrostatic attraction between the positive metal ions and the negative delocalised electrons
is metallic bonding a strong or weak attraction?
Strong
3 metal properties
high melting points, able to conduct electricity and are malleable
Why do metals have high melting points?
The metallic bond bonding is usually very strong so lots of energy is needed to break it
Why can metals conduct electricity?
Because the delocalised electrons are free to move through the lattice
Why are metals malleable?
The layers of metal ions can slide over each other
What is thermal decomposition?
A thermal decomposition reaction is when heat energy is used to break down a substance
Equation for the thermal decomposition of metal carbonates?
metal carbonate –> metal oxide + carbon dioxide
thermal decomposition of copper carbonate with colours?
copper carbonate (green solid) –> copper oxide (black solid) + carbon dioxide (colourless gas)
What is downward delivery?
Carbon dioxide is denser then air so it sinks to the bottom of a test tube and stays there until you want to use it.
3 most reactive metals?
Potassium (K), Sodium (Na), Lithium (Li)
Metal + water equation?
metal + water –> metal hydroxide + hydrogen
Magnesium + water observations?
Effervescence - due to the hydrogen gas produced
Solid disappears - due to being used up in this reaction
What are group 1 metals also called?
alkalimetals
Observations for Li, Na or K 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 reactions
What colour does the universal indicator turn after a group 1 metal and water react?
dark blue
Why are metal hydroxides alkalis?
the donation OH-
Colour of potassium flame?
lilac
Why do the group 1 metals get more reactive as you go down the group?
The atoms get bigger and have move shells
The outer electron is further from the nucleus
The attraction between the nucleus and the outer electron is weaker
So less energy is needed to break the attraction
Metal + steam reaction equation?
metal + steam –> metal oxide + hydrogen
Conducting a magnesium and steam reaction
Conducted in a horizontal tube
Some wet wool is heated to generate steam for the Mg to react with
The hydrogen gas produced is ignited to safely destroy it
Why do metals react with cold water and hot steam to produce different products?
Steam has more energy, so both bonds in the molecule can break - O, H, H
Cold water has less energy, so only one bond can break - H, OH
Why is hydrogen ignited?
To safely destroy it
