Metals and alloys Flashcards
Draw the diagram for metallic bonding
file:///C:/Users/44748/Documents/metallic%20bonding%20and%20alloys.pdf
Define metallic bond
The electrostatic attraction between the positive metal ions and the negative delocalised electrons in a metal
high metal point metals
Describe the structure of a metal
In a metal, the positive metal ions are closely packed together with the negative delocalised electrons and are arranged in regular layers.
How are the atoms arranged in a metal
Metals consist of giant structures of atoms arranged in a regular pattern
Explain why the particles that make up a metal are described as positively charged ions
The particles that make up a metal are described as positively charged ions . This is because, the metal atoms lose their outer shell electrons into a ‘sea’ of (delocalised) electrons,
Therefore, there are more protons (+) than electrons (-)in each metal atom,
more protons (+) than electrons (−), causing the metal ions to become positive.
Define electrostatic attraction
The electrostatic attraction is the attraction between opposite charges
Define delocalised electrons
Delocalised electrons are free-moving electrons within structure that are not associated with a particular atom
What does it mean when electrons have become delocalised
When an electron is delocalised it means that the electron (in the outer shell) are free to move through the whole structure
What does it mean when electrons have become delocalised
When an electron is delocalised it means that the electron (in the outer shell) are free to move through the whole structure
Why are metals good conductors of heat and electricity
Metals are good conductors of heat and electricity.
This is because the delocalised electrons move through the metal lattice structure and carry a charge.
Why are metals malleable and ductile
Metals can be bent and shaped because the layers of positively charged (metal) ions in the giant metallic lattice can slide over each other.
Why do metal s have high melting points
Metals have melting points.
Metals have high melting and boiling points due to their giant structures and the strong electrostatic attraction between all the positively charged ions and the negatively charged electrons.
A lot of energy is required to break the strong metallic bonds (electrostatic attraction between positive metal ions and negatively charged delocalised electrons) and therefore metals have high melting and boiling points.
Define alloy
An alloy is a mixture of two or more elements, at least one of which is a metal.
Explain why metal alloys are harder than pure metals
In an alloy, the different sizes of atoms distorts the layers, making it more difficult for the atoms to slide over each other. This means that alloys are harder than pure metals.
