C3 - Structure and Bonding Flashcards
What is it called when a SOLID turns into a GAS
Sublimation
What is it called when a SOLID turns into a LIQUID?
Melting
What is it called when a LIQUID turns into a SOLID?
Freezing
What is it called when a LIQUID turns into a GAS?
Boiling
What is it called when a GAS turns into a SOLID?
Deposition
What is it called when a GAS turns into a LIQUID?
condensing
What is a covalent bond?
When electrons are shared between non metal atoms
Why do atoms need full outershells?
To be stable
What is the definition of Ionic Bonding?
The electrostatic force of attraction between two oppositely charged ions
Why do lattices have very high melting and boiling points?
They have lots of ionic bonds
This means that the bonds are very strong
Requiring alot of energy to break
What is the formula of hydroxide ions?
_
OH
What is the formula of Sulfate?
2-
SO4
What happens when two non metal elements try and attract? For example Cl and Cl
They share electrons
Which types of elements combine in ionic bonding?
Metals combine with non metals
Why do metals combine with non metals in ionic bonding? For example, Li and Cl
So both elements can have a full outer shell
Li (+1) + Cl (-1) = LiCl
What is an ionic compound?
A giant structure of ions
How are ionic compound held together?
Electrostatic forces of attraction between oppositely charged ions (ionic bonding)
What happens when ionic compounds are melted or dissolved in water?
They conduct electricity
Why do ionic compounds conduct electricity when melted or dissolved in water?
The ions are free and their charge can flow
Where does covalent bonding occur?
Between non - metal elements and compounds of non metals
How are covalent bonds formed?
When atoms share pairs of electrons
What is metallic bonding?
Atoms which share delocalised electrons
What are some examples of giant covalent structures?
Diamond
Graphite
What is an example of a simple molecullar structure?
Water
Why do ionic substances not conduct electricicty when they are a solid?
The ions are in a fixed position and are not free to flow
What does it mean when an atom is delocalised?
It is free to move around the whole structure
Why do positive metal ions attract to delocalised elctrons?
Electrostatic force of attraction
What are the properties of giant covalents?
High melting and boiling points
What are the three main types of covalent structures?
Giant covalents
Small molecules
Large molecules
What are the properties of covalent small molecules?
Low melting and boiling poit
The intermolecular forces are weak so do not require energy
What are the properties of covalent large molecules?
Melting and boiling points are low but still stronger than small molecules
What is the state of giant covalents at room temperature?
Solid
What is the state of covalent small molecules at room temperature?
Gaseous or liquid
What is the state of covalent large molecules at room temperature?
Normally solid
Why do most covalent structures not conduct electricity?
They do not have delocalised electrons or ions that are free to move