C2.3 Flashcards
Why do covalent bonds form between two non-metal elements?
Because they are both short of completing their full outermost shell which they need to complete
What is a double bond?
When two atoms Shan two pairs of electrons to complete their outermost shells
What is a simple molecular, covalent substance?
A substance made of individual small molecules with strong covalent bonds holding the atoms together in the molecule but only weak forces between neighbouring molecules
Why do simple molecular, covalent substances have a low melting and boiling point?
They only have weak bond between neighbouring molecules
What is an electric current?
A flow of charged particles
Why are simple molecular, covalent molecules bad at conducting electricity ?
The atoms inside them have not lost or gained any electrons so they don’t have any charged particles that can move around.
What is a giant molecular, covalent bond?
A substance containing millions of atoms all held together by covalent bonds
Why do giant molecular,covalent bond have a high melting and boiling point?
The atoms inside them are all held together with strong covalent bonds which nee a lot of heat energy to break
What are the two main example of giant molecular, covalent structures formed by carbon?
Diamond and graphite
Why do diamond and graphite have such dissimilar properties?
Because of the different ways the carbon atoms in each of them are arranged
List two properties and a use for diamond?
- is very hard
- does not conduct electricity
- used for cutting tools
List two properties and a use of graphite:
- easily rubs away in layers
- does conduct electricity
- pencils or lubricant
What are immiscible liquids?
Liquids that do not mix completely with each other
How can you separate two immiscible liquids?
By using a separating funnel
What are miscible liquids?
Two liquids that completely dissolve in each other and form a solution
