bonding Flashcards
how do metal atoms bond with each other
(metallic bonding)They form a LATTICE (grid) of IONS surrounded by a ‘SEA’ OF DELOCALISED ELECTRONS.
As the electrons are free to move, metals are good CONDUCTORS of electricity and heat.
how do metal and non metals bond together
(ionic bonding) Meeal aeoms donate elecerons to non-metals to form IONS.
the charge of all ions in an ionic compound must add up to 0
what can the dot and cross diagram be used for and what does it show
DOT & CROSS DIAGRAMS show the electrons on the outer shells. (The arrow isn’t needed). Metals always end up with an empty outer shell, non-metals with 8 electrons.
name characteristics of ionic structures
Ionic substances have HIGH MELTING/BOILING POINTS due to the STRONG IONIC BONDS (as the ions have strong electrostatic forces between them).
what can positive and negative ions can be called
positive ions are also know as cations
negative ions are called anions
what can ionic compounds also be called
called salts e.g sodium chloride
how are ions arranged in a lattice
Ions are arranged in a LATTICE of repeating
units of positive and negative IONS.
These form a crystal.
what can ionic structures do
They can conduce electricity when MOLTEN or in SOLUTION (dissolved). This is because the ions are free to move in these states, and they carry charge.
name molecular ions
hydroxide ion: OH -
sulfate ion: SO -2 4
carbonate ion: CO -2 3
nitrate ion: N0 - 3
ammonium ion:NH + 4
how do non metals bond with each other and what do they consist of
Atoms SHARE electrons to gain FULL OUTER SHELLS.
consist of a pair of shared electrons
what are the characteristics of simple covalent structures
they have a low boiling point due to weak inter molecular forces that need to be overcome
what makes a giant molecule
This results in structures that consist of repeating units of atoms to make what are essentially giant molecules e.g. DIAMOND or SILICON DIOXIDE (‘silica’).
what are some characteristics of giant covalent bonds
Very high melting points as you would have to break the covalent bonds.
what is the ALLOTROPES OF CARBON
(Alloeropes: structures made of the same element but arranged differently).
why does diamond have one of the hardest substances
due to very strong bonds.