Bonding Flashcards
What are the limitations of the particle model?
Particles on solid since atoms are mostly empty Space many particles aren’t spherical.
What happens in ionic bonding?
Metals lose electrons to perform positively charged ions and nonmetals gain electrons to form negatively charged ions
Why positive ions positive?
Because they have more protons than electrons
Why are negative ions negative?
Because they have more electrons and protons
How doYou get from a liquid to a gas?
Evaporating or boiling
How do you get a liquid from a gas?
Condensing
Describe The structure of an ionic lattice
And ionic compound is a giant structure of ions. They have a regular repeating arrangement called an ionic lattice. The lattice has formed because the ions attract each other.
Name the properties of an ionic bond
They are held together by strong electrostatic forces of attraction between oppositely charged ions. They have a high boiling and melting point because the energy needed to break the electric static forces of attraction are high.
When can ionic bonds conduct electricity and why?
They can only conduct electricity when it is melted to form a liquid or dissolved in water to form an aqueous solution. This is because the particles are charged and free to move.
What is a covalent bond?
When two atoms share a pair of electrons, it occurs in nonmetals
What do covalent bonds have?
Weak intermolecular forces
Why do covalent bonds have low boiling and melting points?
Because they are held gather with weak into molecular forces and they need little energy to overcome these forces
Why can’t covalent bonds conduct electricity
Because they have no charged particles
What are giant covalent substances joined by?
Many atoms joined by covalent bonds
Why do giant covalent substances have a high melting and boiling point?
Because they are held together by strong covalent bonds that need a lot of energy to overcome
What are diamond and graphite?
Different forms of carbon giant structures of carbon atoms joined together by Covalent bonds
Give the structure of diamond
It is a giant covalent structure and each carbon atom is joined to four other carbon atoms by strong bonds
What network structure do carbon atoms and diamond form?
A regular tetrahedral
Give the properties of diamond
There are no free electrons and it is very hard due to a rigid network of carbon atoms held together by strong covalent bonds. It has a high melting point and doesn’t conduct electricity.
What is the structure of graphite?
It is a giant covalent structure and each carbon atom forms three covalent bonds with other carbon atoms
What are the layers like in graphite?
They form layers of hexagonal rings however there are no covalent bond between layers and there is one non-bonded or delocalised electron from each atom
Name the properties of graphite
Has delocalised electrons that are free to move between the layers and therefore they can conduct electricity
What is graphite useful for?
Electrodes and electrolysis
Why is graphite a good lubricant?
Because the forces between the layers are weak and they can slide over each other easily making it slippery
What is graphene?
A single layer of graphite
What is the structure of graphene like?
There were strong covalent bonds between carbon atoms
What are the properties of graphene and why?
It has a high melting point and is very strong due to strong covalent bonds and it conducts electricity due to delocalised electrons
What is graphene useful for ?
Electronics and making composites
What is the structure of fullerenes like?
large molecules of carbon atoms with hollow shapes, based on hexagonal rings joined by covalent bonds includes five or seven carbon atoms
What are two examples of fullerenes?
Buckministerfullerene and nanotubes
Buckministerfullerene structure
Molecules are made up of 60 carbon atoms joined together by strong covalent bonds
What are the properties of Buckministerfullerene and why?
It has a low melting point and is slippery because it has weak intermolecular forces that need little energy to overcome
What is the structure of nanotubes like?
It is like a layer of graphene in a cylinder and has a high length of diameter ratio high tensile length and strong in tension and resist being stretched
Why do nano tubes conduct electricity?
They contain delocalised electrons
Give the structure of polymers
They have very large molecules and atoms are joined together by strong covalent bonds in long chains
Give the properties of polymer
They have strong covalent bonds between molecules so they have a high melting point and they are solid at room temp
Give the structure of metals
Consist of joint structures of atoms arranged in a regular pattern electrons from outer shells are delocalised and free to move through throughout the whole structure
Give the properties of metals and why
They’re all good electrical conductors as their electrons can carry charge. They are good conductors of thermal energy due to the delocalised electrons transferring energy. They are a high melting and boiling point as a metallic bonding in the giant structure of the metal is very strong.
What is an alloy?
A mixture of two or more elements where one element is a metal
Why are alloys hard?
They have atoms of different sizes and so it distorts the layers of the atoms making it hard for them to slide over each other
