Topic 5- Bonding 📄/📄📄 Flashcards
What is an ion?
A charged particle
What is a bond?
Forces of attraction which hold atoms together
Why do atoms bond?
To become more stable, by achieving noble gas configuration
What do metals form when they bond ionically?
Cations
What do non metals form when they bond ionically?
Anions
When is an ionic bond formed?
When valence electrons are transferred from one atom to another to complete the outer shell electron
What determines whether atoms gain or lose electrons?
The number of electrons on the outer shell, also known as the group number
What is meant by noble gas configuration?
Ions have a full outer shell of electrons which is the same as the electronic configuration of atoms in group 0
What is an ionic lattice?
Millions of ions are packed together in a regular cubic arrangement and are joined by covalent bonds. This forms a giant 3D structure known as an ionic lattice.
Lattice= regular repeating pattern
What holds ions together?
Strong electrostatic forces of attraction which are difficult to break
What is the charge of ionic compounds?
There is no charge. The ions are charged and overall the charges cancel each other out
What do you have to do in order to cancel out the ionic charges?
Finding the lowest common multiple
(Or crossing charges over)
When non metals form ions the suffix changes to..
IDE
Example: How is calcium chloride formed?
Each calcium loses 2 electrons to become Ca2+ and each chlorine gains 1 electron to become Cl-. 2 chlorine atoms are needed for every calcium atom. This forms MgCl2, overall charge is 0 as the ions cancel each other out
What are 3 properties of ionic compounds?
High melting and boiling points
Brittle
Only conduct when molten or in solution
Explain the property of ionic compounds
High melting and boiling points
There are strong electrostatic forces of attraction between oppositely charged ions. These require a lot of energy to break
Explain the property of ionic compounds
Brittle
Like charges repel when the layers are shifted, this causes the ionic lattice to shatter
Explain the property of ionic compounds
Only conduct electricity when in solution or molten
Because the ions are free to move and carry charge
What are polyatomic ions?
Sometimes there are more than 2 atoms involved in the bonding, sometimes they can contain more than one atom
What is the ionic charge of carbonate?
CO3 2-
What is the ionic charge of hydroxide?
OH-
What is the ionic charge of ammonium?
NH4 +
What is the ionic charge of sulfate?
SO4 2-
What is the ionic charge of nitrate?
NO3 -
What happens in covalent bonding?
Electrons are shared
What forms covalent bonds?
Non metals
What holds covalent bonds together?
Strong electrostatic forces of attraction, strong covalent bonds
What state are covalent bonded molecules at room temperature?
Liquid or gas
What are some examples of covalent bonded simple molecules?
Water
Oxygen
Carbon dioxide
Bromine
Hydrogen
What is a covalent bond?
A shred pair of electrons
What is a covalent bond?
A shred pair of electrons
What are 3 properties of covalents?
Liquid or gas at room temp
Don’t conduct
Weak intermolecular forces
Explain the covalent property of liquid or gas at room temp
Forces between moelcules are relatively weak so don’t take a lot of energy to break.
Explain the covalent property of not conducting electricity
Made up of non metals
Explain the covalent property of low melting and boiling points
Weak intermolecular forces don’t require a lot of energy to break
What are polymers?
Long chains of monomers joined together
How are polymers made?
A double bond that opens to join more monomers together
How do you name polymers?
Poly in front of monomer name
What are 3 properties of polymers?
Solid at room temp
Polymers chains intertwined
Many intermolecular forces along chains require a lot of energy to break
What are allotropes?
Different forms of the same element
What is the arrangement of the giant covalent diamond?
Tetrahedral
What is diamond made of?
Carbon
Does diamond conduct electricity?
No
Each carbon atom is covertly bonded to 4 other atoms so there are no delocalised ejections to carry charge
What are some uses of diamond?
Drill bits
Jewellery
What are some uses of diamond?
Drill bits
Jewellery
What are the bonds like in diamond?
Strong covalent bonds require a lot of energy to break
What is graphite made of?
Carbon
What are uses of graphite?
Pencils, good equipment, lubricant, electrodes
What are the forces like in graphite?
Weak so layers can easily slide over each other
What’s the arrangement in graphite?
Hexagonal
Can graphite conduct electricity?
Yes
Each atom is bonded to 3 others leaving one delocalised electron which can move and carry charge
What are the bonds like in graphite?
Solid at room temp as there are lots of strong covalent bonds
What are fullerenes?
Simple molecules
Example of fullerenes
Buckminster
Nanotube
What are fullerenes made of?
Carbon making them an allotrope of carbon
What are some properties of fullerenes?
Low melting and boiling points meaning there are weak intermolecular forces
Strong covalent bonds between molecules
Can fullerenes conduct electricity?
Yes, each carbon atom is covalent bonded to 4 others meaning it can conduct across the surface as die to 1 free electron which
What is graphene?
An allotrope of carbon which is an individual layer of graphite, one layer thick
Is graphene simple or giant covalent?
Giant
Can graphene conduct electricity?
Each carbon atom is covalent bonded to 3 others the one free electrons conducting across the surface
What are the 5 bonding models?
- Dot and cross
- Ball and stick
- Displayed formula
- 3D space filling model
- Ionic models
Advantages of dot and cross diagrams:
Shows where electrons come from
Can easily draw to identify formula
Shows how electrons are shared
Easy to identify which atoms/ions
Disadvantages of dot and cross diagrams
Doesn’t show fact that electrons move
Only show outer electrons
Could imply electrons are different atoms due to crosses and dots
Doesn’t show relative side of atoms
Doesn’t show it in 3D arrangement
Advantages of ball and stick model and displayed formula
Can easily identify formula Shows
Clearer for large repeating units
Can show if molecule is 3D
Easier to identify single, double bonds
Disadvantages of ball and stick and displayed formula
Doesn’t show where electrons come from
Doesn’t show relative size of atoms
Doesn’t show 3D arrangement unless3D model
Implies atoms are held with sticks
Can’t see attending of electrons
Advantages of 3D space filing model
Shows relative size of atoms Doesn’t
Can show which atoms are bonded
Shows 3D arrangement
Disadvantages of 3D space filling model
Die yes always show what atoms they are
Doesn’t show electrons involved in binding
Doesn’t show the bonds formed and number
Advantages of ionic models
Shows lattice arrangement
Explains why they conduct electricity
Shows charges
Disadvantages of ionic models
Doesn’t show relative size of ions
Doesn’t always show which ion is which
Doesn’t show vibration of ions
(Not quick to draw)
