Topic C2 (structure , bonding and properties ) Flashcards
Name the three states of matter
solid , liquid and Gas
How do you turn a liquid into a gas ?
Boiling
How do you turn a gas into a liquid ?
Condensing
How do you turn a solid into a solid ?
Melting
How do you turn a liquid into a solid
freezing
Why do some substances have a higher melting point than others ?
The boiling points of a liquid depends on the forces between the particles
Define aqueous
This means it can be dissolved in water
Why do objects want to react with each other ?
To gain a full outer shell by gaining or loosing electrons
Name the three types of bonding
Ionic , covalent and metallic
What is a ionic bond ?
When a metal and a non metal react. The non metal shares electrons to fill up the outer shells and create a strong covalent bond. A non metal gains electrons and become negative
What is a metallic bond ?
When metals react with other metals. They let go of their outer shell and so the electrons move around freely (sea of electrons)
What is a covalent bond ?
A covalent bond, also called a molecular bond, is a chemical bond that involves the sharing of electron pairs between atoms.
Why do particles together in an ionic bond ?
because the particles are attracted to each other
What happens to the electrons when a covalent bond forms ?
Their shared
Name three ways in which a covalent bond are different from ionic bonds
There’s no charge, shared electrons and two non-metals
What happens to the atoms when a metallic bond takes place ?
The atoms before the bond are closely packed together but once it takes place the electrons become delocalised and can move around freely creating a sea of electrons
Why are metals strong and have high melting points ?
There is a strong attraction (electrostatic)
This attraction gets stronger if more electrons are in the sea of electrons
Why do metals conduct electricity
The delocalised electrons will move if a voltage is applied across metal
This allows metals to conduct electricity
Why do metals conduct heat ?
The metal particles are very close together so they can pass heat quickly
The delocalised electrons also move faster when heated
Why can metals from crystals ?
Because they are arranged into a big lattice
What forms the sea of electrons ?
When the metals let go of the electrons
What holds the positive ions in a metal ?
The sea of electrons
What happens to metallic bonding once it melts
It breaks down !!!!!
What does it mean if the attraction between molecules are weak ?
does not need a lot of energy to break the bond
Why cant covalent bonds conduct electricity ?
They do not have a positive or negative charge
What are intermolecular forces ?
The forces between the molecules
What is diamond made of ?
Carbon and each carbon has 4 bonds
What is graphite made of
Carbon with 3 bonds
what is fullerenes
The strongest metal ever found
very good conductors of heat and electricity and can be used as a catalyst
Why is diamond so hard ?
Because the bonds are very strong so it takes a lot of energy to separate it
Why cant diamonds conduct electricity
because they don’t have any electrons
What do we commonly use graphite for ?
Pencil lead
Why can graphite conduct electricity and heat ?
Because it has delocalised electrons
What is a polymer ?
Plastic with a huge chain
What does n stand for ?
How many monomers there are
Why are intermolecular forces between polymer chains stronger than the intermolecular forces between small molecules ?
Because polymer chains are longer which makes them stronger
Why don’t polymers soften when heated ?
The bonds are too strong
