topic 1.3 bonds Flashcards
How do ionic bonds form
Metal and non-metal react together
The metal loses a electron to form a positive ion (cation) and non metal gains an electron to form a negative ion (anion) to get a full outer shell.
These charges strongly attract one another by ELECTROSTATIC FORCES.
what diagram do you use to show how they are formed
dot and cross
what is an ion
charged particles- can be single atoms or groups of atoms
how do you calculate number of electrons and protons in a ion
charge of atom + atomic number
e.g. Na1+ has 11 - 1 electrons= 10
why are groups 1, 2, 6 ,7 most likely to form an ion
1 and 2 are metals and lose an electron
6 and 7 are non metals that gain an electron
when do ionic compounds have the ending -ide
when it contains just two elements
when do ionic compounds have the ending -ate
when it contains three or more elements
what structure does ionic compounds have
Regular lattice
- have very strong electrostatic forces of attraction between oppositely charge ions
- has a regular and uniform arrangements of ions
how does covalent bond form
When a pair of electrons is shared between two atoms.
what does covalent bonding result in
Formation of a molecule
What are the properties of ionic compounds
-High melting and boiling points due to strong attraction between ions.
- Solid ionic compounds don’t conduct electricity.
- liquid compounds can conduct as ions are free to move
- many dissolve in water and as aqueous solution ions free to move
what are the properties of typical simple molecular substances (covalent bonded)
-atoms whithin the molecule held together by very strong covalent bonds.
-Forced of attraction between molecules are very weak (intermolecular forces)
-melting and boiling point are low
-As molecules get bigger the intermoleculat forces strength increases.
-Don’t conduct
what are graphite and diamonds structure
giant covalent substances
made of carbon
describe diamonds structure
rigid lattice strucure
made of network of carbon with four bonds each
strong covalent bonds
Describe graphite strucure
Each carbon atom only has three bonds, creating sheets of carbon.
No covalent bonds holding layers together so are free to move.
high melting point- layers need a lot of energy.
only 3 carbon bonds so have delocalised electron that can conduct electricity.
what are fullrenes
Molecules of carbon shaped like closed tubes or hollow spheres.
Used to “cage” in other molecules (used to deliver drug directly to cells).
Large surface area ( make great industrial catalysts.
what is Graphene
(A type of fullrene)
one layer of graphite
one atom thick making it a two-dimensional compound
what are polymers
covalently bonded carbon chains.
formed when lots of monomers join together.
describe metalic bonding
delocalised electron in outer shell.
Strong electrostatic attraction between the positive metal ions and electrons.
These forces hold the atoms together in a regular structure known as metallic bonding.
very strong
properties of metal
strong electrostatic forces means very high melting and boiling points.
So are shiny solids at room temperature.
more dense than non-metals.
Layers of atoms in pure metals can slide over one another and make it malleable.
conduct electricity.
Non-metals vs metals
Non-metals-
low boiling point and poor conductors of electricity
metals-
shiny, high boiling point and good conductors of electicity
