3.1 Metals Flashcards
What are the properties of metallic bonding?
- Electrostatic force of attraction between positively charged ions and delocalised electrons
- High melting amd boiling points
- Always conductive
Why do metals conduct electricity?
Because they contain delocalised electrons
What does malleable mean?
Able to be hammered or pressed into shape without breaking
What does ductile mean?
Able to be drawn into a thin wire
How is the method of extraction of a metal determined?
It’s position on the reactivity series
What is a native metal?
A metal that is so unreactive they can be found uncombined in nature in large amounts (e.g. gold and platinum)
Where is a native metal on the reactivity series?
Right at the bottom
Which elements can be extracted by heat alone?
Elements below copper on the reactivity series (gold, silver and mercury)
What does extraction by heat alone mean?
The metal will separate from its ore when heated
Which elements can be extracted by heating with carbon/carbon monoxide?
The elements between copper and zinc (inclusive) on the reactivity series
What does extraction by heating with carbon/carbon monoxide mean?
The element will separate from its ore when heated with carbon/carbon monoxide
How is iron extracted from its ore?
In a blast furnace, which keeps the temperature above 2000°C
Which metals require electrolysis to extract from their ores?
Metals above zinc in the reactivity series
What is electrolysis?
The decomposition of an ionic compound into its elements using electricity
What happens during electrolysis?
Positive ions gain electrons at the negative electrode and negative ions lose electrons at the positive electrode
What is reduction?
Reduction Is Gain of electrons by a reactant in any reaction (the way they appear on the electrochemical series)
What is oxidisation?
Oxidisation Is Loss of electrons by a reactant in any reaction (the reverse of the way they appear on the electrochemical series)
What is a redox reaction?
A reaction where reduction and oxidisation take place at the same time
What do metals and non metals do in ionic compounds?
Metals lose electrons to form positive ions
Non metals gain electrons to form negative ions
Metal+oxygen makes…
Metal oxide
Metal+water makes…
Metal hydroxide+hydrogen
Metal+dilute acid makes…
Salt+oxygen
What is the reactivity series
An arrangement of metals created by ordering them in terms of reactivity (the rate at which they react)
How do you create a redox reaction?
By combining the separate reduction and oxidation reaction so the electrons cancel out
Which way around are reactions written in the table?
Reduction (flip the top one in the redox equation)
What happens when the metals are extracted from their ores?
The metal ions are reduced to form metal atoms
What is electrolysis?
The decomposition of an ionic compound into its components using electricity
What happens during electrolysis?
A D.C. current must be used
Positive ions gain electrons at the negative electrons
Negative ions lose electrons at the positive electrode
What is corrosion?
The deterioration of a metal when it is exposed to water and oxygen
What is rusting?
The corrosion of iron
What is ferroxyl indicator?
An indicator that turns from yellow to blue in the presence of iron ions
What are different forms of protection against rusting?
- Painting
- Coating with oil or grease
- Metal plating (when plated with zinc this is called galvanising
- Dehumidification
- Sacrificial protection
- Attatching to the negative terminal of a power source
