C2 - Bonding, Structure and Propeties Flashcards
Describe how particles are arranged in a solid
Closely packed, regular and vibrate in a fixed position
Describe how particles are arranged in a liquid
Closely packed, irregular and slide past each other
Describe how particles are arranged in a gas
Spaced apart, move in random direction
Between what kind of elements form metallic bonds?
Metals
Between what kind of elements form ionic bonds?
Metals and nonmetals
Between what kind of elements form covalent bonds?
Nonmetals
What happens to electrons in ionic bonds?
Transferred from one atom to the other ie. form ions
What happens to electrons in covalent bonds?
Shared
What happens to electrons in metallic bonds?
Delocalised over the structure
When metals lose electrons what charge will they have?
Positive
When nonmetals lose electrons what charge will they have?
Negative
Describe the structure of a metal
Giant lattice of positive metal ions with delocalised electrons
Why do metals have high melting points?
They have strong electrostatic forces between positive ions and electrons
Why do metals conduct electricity?
They have delocalised electrons that are free to move and carry charge
Why are metals malleable?
Their layers can slide past each other
What is an alloy?
A mixture of two or more atoms, where at least one is a metal
Why are alloys harder than pure metals?
Atoms are different sizes and distort the layers so they don’t slide past each other
Why do atoms want to lose / gain electrons when they react?
They want to have full outer shells
Describe the structure of an ionic compound
Giant lattice of oppositely charged ions
Why do ionic compounds have high melting points?
Strong electrostatic forces between oppositely charged ions need lots of energy to break
Why do ionic compounds not conduct electricity when solid?
The ions are not free to move
Why do ionic compounds not conduct electricity when solid?
The ions are not free to move
What element is diamond and graphite made from?
Carbon
Describe the structure of diamond
Every carbon atom forms 4 covalent bonds with other carbon atoms
Describe the structure of graphite
Every carbon atom forms 3 covalent bonds with other carbon atoms forming layers of hexagonal rings. Weak intermolecular forces between layers
Why do diamond and graphite have high melting points?
They have lots of covalent bonds that are strong and need lots of energy to break
Why is diamond hard?
Lots of covalent bonds that are strong and hard to break
Why do ionic compounds conduct electricity when molten / dissolved in a solution?
The ions are free to move and carry charge
Give some examples of simple covalent molecules
Cl2, F2, O2, CO2, H2O, HCl
Give examples of giant covalent structures
Diamond, graphite, silicon dioxide
Why do simple covalent molecules, like O2, have low boiling points?
They have weak intermolecular forces between molecules