Chemistry Topic 2 - Bonding, Structure and Properties of Matter Flashcards
Ions are made when…
Electrons are transferred
Define Ions
Charged Particles
When metals form ions…
They lose electrons and form positive ions
When non-metals form ions…
They gain electrons and form negative ions
What happens in ionic bonding
metal atom loses electron to form positive ion and non-metal gains electron to form negative ion. these oppositely charged ions are strongly attracted to one another by strong electrostatic force of attraction
Describe the structure of an ionic compound
The ions form a closely packed Regular Lattice Structure and they have very strong electrostatic forces of attraction between oppositely charged ions in all directions.
Ionic compound properties (3 marks)
. High melting and boiling point due to strong bond
. When solid ions are held in place so cannot conduct eletricity
. When melted, ions seperate and are free to move and carries electric current and conduct electricity
What happens in Covalent bonding
Bonding between non-metals where they share a pair of electrons to make covalent bonds.
Why is Covalent Bonds strong
The positively charged nuclei of the bonded atoms are attracted to the shared pair of electrons by electrostatic force of attraction making them strong
Why do atoms want to have a full outer shell
it gives them electronic structure of noble gases, which is very stable.
What has a simple molecular structure
Substances containing covalent bonds
Properties of simple molecular substances
Dont conduct electricity because they arent charged so no free electrons or ions
As they get bigger, melting and boiling point increases because intermolecular forces increase so more energy required to break them.
In which state are most simple molecular substances at room temp
Liquids and Gases
What forces need to be overcome to boil a simple molecular compound
Intermolecular forces need to be overcome
What are polymers
Long chains of repeating units joined by strong covalent bonds