Bonding, structure and properties of matter Flashcards
Ions are
charged particles - they can be single atoms of group. They are made when electrons are transferred.
When metals
form ions , they lose electron from outer shell to form positive ions
When non-metals ion
they gain electrons to form negative ions.
Group 1 and 2 elements
lose electrons to form positive
Group 6 and 7 elements
gain electrons to form negative
ionic bonding
non-metal + metal when ions are oppositely charged ions and strongly attracted to each other by electrostatic forces
ionic compounds
have a regular lattice structure and giant ionic lattice.
with ionic compounds
the ions form a closely packed regular lattice arrangement and very strong electrostatic forces of attraction between oppositely charged ions .
A single crystal of sodium chloride
is one giant ionic lattice .
Ionic compounds have similar properties
They all have high melting points and boiling points. When solid - ions are in place so they cants conduct electricity . When melted the ions are free to move and carry an electric charge .
Covalent bonding
non- metal bonds together and share pairs of electrons. Positively charged nuclei of the bonded atoms are attracted to the shared pair of electrons by electrostatic forces making bond strong
Simple molecular substances
are made up of molecules containing a few atoms joined together by covalent bonds
Examples of simple molecule substances
Hydrogen - 1 electron
Oxygen - need 2 electron for full outer shell
Methane - can form four covalent bonds with hydrogen atoms to fill its outer shell
Properties of simple molecular substances
To melt of boil you need to break the feeble intermolecular forces and not the covalent bond . As molecules get bigger the strength of the forces increase. Melting point and boiling points are very low . Molecular compounds don’t conduct electricity
Substances with covalent bonds .
usually have simple molecular structures