The metallic model - properties of metals & their uses Flashcards
What is metallic bonding?
Metal atoms are tightly packed together in lattice structures
In metallic bonding, the electrons in their outer shells are free to move throughout the structure.
What are delocalised electrons?
Electrons that are not bound to their atom and can move freely throughout the metallic structure
Delocalised electrons contribute to metallic bonding and conductivity.
What happens to metal atoms when electrons are delocalised?
The metal atoms become positively charged
The positive charges repel each other, maintaining the lattice structure.
What are the properties of metals?
Malleability, strength, electrical conductivity, thermal conductivity, high melting and boiling points
These properties result from metallic bonding and the structure of metals.
What is malleability in metals?
The ability of metallic compounds to be shaped without breaking
When a force is applied, metal layers can slide and reform metallic bonds.
What contributes to the strength of metallic compounds?
The strong attractive forces between metal ions and delocalised electrons
This strong attraction makes metals hard and durable.
How do metals conduct electricity?
Through the movement of mobile electrons in solid or liquid states
Delocalised electrons repel from the negative terminal and move towards the positive terminal when a potential difference is applied.
As the number of outer electrons increases across a Period, what happens to electrical conductivity?
The ability to conduct electricity increases
For example, sodium has 1 outer electron, while aluminium has 3 outer electrons.
What is thermal conductivity in metals?
The ability of metals to conduct heat effectively
This is due to the vibration of cations and the movement of delocalised electrons.
What causes high melting and boiling points in metals?
Strong electrostatic forces of attraction between cations and delocalised electrons
Large amounts of energy are required to overcome these forces.
What factors are considered when choosing a metal for a particular use?
Malleability, electrical conductivity, thermal conductivity, melting/boiling point, strength, strength-to-weight ratio, density, toxicity, corrosion resistance, reactivity, lustre, sonority
Each property influences the suitability of a metal for specific applications.
Why is aluminium used in food cans?
It is non-toxic and resistant to corrosion and acidic foodstuffs
Aluminium’s properties make it ideal for food packaging.
Why is copper used in electrical wiring?
It is a good electrical conductor and is malleable/ductile
Copper’s properties allow for effective and flexible wiring solutions.
What is the use of stainless steel?
It is used for cutlery due to its strength and corrosion resistance
Stainless steel’s properties make it suitable for kitchenware.
