3-Bonding Flashcards
Noble gases
Only group that exist as individual atoms not bonded to other atoms, monatomic elements, their outer energy level of electrons is full making it stable therefore very unreactive
Why do atoms form bonds?
To have a full outer energy level and to achieve a stable electron arrangement
Covalent bonding
Two non metal atoms share electrons, its the strong electrostatic attraction between the positively charged nuclei of each non metal atom and the shared pair of negatively charged electrons, strong bonds
Covalent molecular
Atoms that share pairs of electrons form molecules
Molecule
Group of atoms held together by covalent bonds
Diatomic molecules
A molecule containing only two atoms. Hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, iodine
Bonding diagrams
Show how the outer electrons are shared, to make atoms outer electrons stable
Covalent compound
Same rules apply, bigger molecules
Covalent molecules
2 atoms= linear= O-O
3 atoms= angular
4 atoms= trigonal pryrimidal
5 atoms= tetrahedral
Covalent networks
Made up of non metal atoms which are joined together by covalent bonds in a giant network structure
Structure egs: boron, carbon, silicon
Covalent molecular solubility, melting and boiling points, electricity conductors?
Covalent molecular substances which are not soluble in water may dissolve in other solvents
Have low melting and boiling and melting points as only weak forces of attraction between the molecules are broken when a substance changes state
Covalent molecular substances do not conduct electricity because they don’t have charged particles which are free to move
Covalent network solubility, melting and boiling points, electricity conductors?
In general, covalent network substances do not conduct electricity, graphite is an exception because it has delocalised electrons in its structure
do not dissolve
have very high melting and boiling points because the large network of covalent bonds is not easily broken
Ionic bonding
Non metal and metal join
Ionic bond is a strong electrostatic attraction between positive metal ions and negative non metal ions
In ionic bonding, metals are oxidised and non metals are reduced
Reduction
Is a gain f electrons y a reactant in any reactions
Oxidation
A loss of electrons by a reactant in any reactions
Ionic compound solubility, conducting electricity and the melting and boiling points
Most ionic compounds are soluble in water because as it dissolves, water molecules surround the separated ions.
ionic compounds have high melting and boiling points because they have strong bonds. When ionic compounds are molten they can conduct electricity because they contain charged particles (ions) but when solid the ions are free to move so molten ionic compounds conduct electricity and solid ionic compounds don’t conduct electricity
Explain electrolysis
The positive ions are attracted to the negative electrode, when they get to the electrode, they pick up two electrons.
The negatively charged ions are attracted to the positive electrode when they get to the electrode they lose their extra electrons.
Electrolysis
The breaking of a compound by passing electricity though it
Direct current
Must be used in electrolysis, direct current allow one electrode to remain positive and the others to remain negative and this allows the product to form at separate electrodes
Electrolyte
A substance which conducts electricity in solution or as a melt
