C4g-Metal Structure and properties Flashcards
Why is iron used to make cars and bridges?
Strong
Malleable
Why is copper used to make electrical wiring?
Good conductor of electricity
Easily bent
What are the physical properties of metals?
- Lustrous
- Hard
- High density
- High tensile strength
- High melting and boiling points
- good conductor of heat and electricity
What properties do you need for a good saucepan?
- good conductor of heat
- doesn’t rust easily
What properties do you need for a good aeroplane?
- low density(light)
- strong
- doesnt corrode
What are the particles in a metal held by?
Particles in a metal are held together by metallic bonds
What is metallic bonding?
The strong attraction between a sea of delocalised electrons and close packed positive metal ions
Why do metals have high melting points and boiling points?
They have strong metallic bonds which need a lot of energy to break them apart
Why do metals conduct electricity?
There is a sea of delocalised electrons which move freely through the metal, carrying the electrical current
What is a superconductor?
When you make a metal cold enough and their resistance disappears completely
What are the benefits of superconductors?
- transmit electricity without any loss of power
- strong electromagnets don’t need a constant power source
- fast electronic circuits because of no resistance
What are the disadvantages of superconductors?
Difficult and expensive to get a metal to very cold temperatures
