Covalent Bonding And Ionic Compounds Flashcards
What type of atoms do covalent bonds form between
Non metal
When does a covalent bond form
When two positive nuclei are held together by their common attraction for a shared pair of electrons
Name the 7 diatomic molecules
Hydrogen Nitrogen Oxygen Fluorine Chlorine Bromine and iodine
What are the different shapes of simple covalent bonds
Linear, angular, trigonal pyramidal, tetrahedral
How would u describe covalent molecular substances
They have strong covalent bonds within the molecules and only weak attractions between the molecules
They have low boiling points
They do not conduct electricity because they don’t have charged partials that are free to move
Although they may dissolve in other solvents what are molecular substances insoluble in
Water
How would you describe a covalent network structure
They have a network of very strong bonds within one giant structure
They have a very high melting and boiling point
They do not dissolve
Why don’t covalent network substances conduct electricity
Because they don’t have charged particles which are free to move
Why do covalent molecular substances have such low melting and boiling points
Because only weak forces of attraction between the molecules are broken when a substance changes state
Why do covalent network structures have such high melting and boiling points
Because the network of strong covalent bonds is not easily broken
When are ions formed
When atoms lose or gain electrons to obtain the stable electron arrangement of a Nobel gas
When metal atoms lose electrons what type of ions do they form
They form positive ions
When non metal atoms gain electrons what type of ions do they form
Negative ions
Do metal atoms lose or gain electrons
They lose electrons
Do non metal atoms lose or gain electrons
They gain electrons
What are ionic bonds
They are the electrostatic attraction between positive and negative ions
What do ionic compounds form
Lattice structures of oppositely charged ions with each positive ion surrounded by negative ions and each negative ion surrounded by positive ions
Why do ionic compounds have high melting and boiling points
Because strong ionic bonds must be broken in order to break up the lattice
What are many ionic compounds soluble in
Water
What happens as the ionic compounds dissolve
The lattice structure breaks up allowing water molecules to surround the separated ions
Why do ionic compounds only conduct electricity when molten or in solution
The lattice structure breaks up allowing the ions to be free to move
What causes conduction in ionic compounds
The movement of ions towards oppositely charged electrodes
What is electrolysis
Electrolysis is the decomposition of an ionic compound into its elements using electricity
Why must a d.c be used
To identify the products of electrolysis
What happens to positive ions at the negative electrode
They gain electrons
What happens to the negative ions at the positive electrode
They lose electrons
What happens to the negative ions at the positive electrode
They lose electrons
How can u work out the charge of an ion
Metals are always positive and have a charge that corresponds to their group number. Non metals are always negative and have a charge that corresponds to their valency
