C2.2 - Bonding Flashcards
What does malleable mean?
Bends without shattering
What does brittle mean?
They shatter when hammered
What does ductile mean?
They can be pulled into wires
What happens if a substance is non-ductile?
They snap when pulled
What is the appearance of metals?
Shiny
What is the appearance of non-metals?
Dull
Where are melting points and boiling points for metals?
Usually high
Where are melting points and boiling points for non-metals?
Usually low
What state are metals in room temperature?
Solid (except mercury)
What state are non-metals at room temperature?
Around half are solid
Around half are gas
Metal oxides produce alkaline/acidic solutions?
Alkaline
Non-metal oxides produce alkaline/acidic solutions?
Acidic
How are ions formed?
A metal transferring atoms in their outer shell to a non-metal to have a stable outer shell.
What is a covalent bond?
A shared pair of electrons between two non-metal atoms to complete their outer shells
What is a giant ionic lattice?
Ionic compounds containing positive and negative ions arranged in a regular way
What are ionic bonds?
The strong electrostatic forces of attraction between oppositely charged ions (metals and non-metals)
What are the limitations of the ball-and-stick model?
Exaggerated size of atoms
Exaggerated bond lengths
What are intermolecular forces?
Weak forces of attraction between molecules
Which types of polymers have cross-linking?
Thermosetting
What are allotropes?
Different forms of the same element with different atomic arrangements.
Eg diamond
Why doesn’t diamond conduct electricity?
There are no delocalised electrons
Why does graphite conduct electricity?
It has delocalised electrons
What are the typical sizes of nanoparticles?
1-100nm
x10-9m
What are delocalised electrons?
The outer electrons from each atom are able to abandon the nucleus and move freely throughout the metal.
What do delocalised electrons allow?
This allows metals to conduct
How to calculate surface area to volume ratio?
Surface area/volume
What are metallic bonds?
The attraction between positive metal ions in a lattice and their delocalised electrons
What is the key difference between thermosoftening and thermosetting polymers?
Thermosetting polymers have chains joined together by strong covalent bonds called cross links
