C3 Flashcards
What are ions
Charged particles
Why do atoms want to lose or gain electrons to form ions?
To form a full outer shell and become stable
What are positive ions called
Cations
What are negative ions called
Anions
What is ionic bonding
Transfering of electrons
What happens when a metal and non metal react togehter
Metal atoms loses electrons to form a positively charged ion and the non metal gains these electrons forming a negativelt chwrged ion. These oppositely charged ions are strongly attrachted to one another by electrostatic forces. This attraction is called ionic bond
How do to show how ionic compounds are formed ?
Dot and cross diagram (pg113)
What structure do ionic compounds have
Gaint ionic lattice. The ions form a closely packed regular lattice arrangment and there are very strong electrostatic forces of attraction between oppositely charged ions
What are the properties of ionic compounds?
They all have high melting points, many strong bonds between ions, takes alot of energy to overcome attraction. When they are solid, can’t conduct electricity and when they melt they are free to move and they carry electrical charge.
How do you work out the empirical formula of an ionic compound?
Look at diagram to work out what ions are in the compound. Then work out the charges in which the ions will form. Then balance the charges (bottom pg114)
When are covalent bonds created
When non metal atoms bond together sharing pair electrons to make covalent bonds
What makes covalent bonds very strong
The positively charged nuclei of the bonded atoms are attracted to the shared pair of electrons by electrostatic forces
What does each single covalent bond provide
1 extra shared electron for each atom
Why is O2 a gass at room temperature
Because most molecular substances are gases or liquid at room temperature because very little energy is required to overcome these forces
Why does methane have a higher boiling point than hydrogen
Because the more intermolecular forces, the more energy is needed to break them down therefore the melting and boiling point increases
Why does nitogen not conduct electricity
Because molcular compounds do not conduct electricity because they arn’t charged so there are no free electrons or ions
What is a polymer
large molecule made up of repeating subunits known as monomers
How are all atoms in a polymer joined
Strong covalent bonds