Electrical Conductivity and Metals Flashcards
(12 cards)
What is electric current?
A flow of electrons or ions
What types of charge do electrons and ions have?
Electrons: negative charge
Ions: can be positive or negative
When can a material conduct electricity?
When electrons or ions are free to move
Why don’t solid ionic compounds conduct electricity?
Ions are locked in place and can’t move
When can ionic compounds conduct electricity?
When melted (molten)
When dissolved in water (in solution)
Why can molten or dissolved ionic compounds conduct electricity?
Ions are free to move
Why don’t covalent compounds conduct electricity?
No charged particles (except for graphite)
Define metallic bonding
The electrostatic attractions between the nuclei of the positive ions & the electrons.
The electrostatic attraction between positive metal ions and delocalised electrons.
Why are metals good conductors of electricity and heat?
Delocalised electrons can move through the structure
Electrons transfer energy quickly
What are delocalised electrons?
Also called free electrons
Electrons not bound to one atom and can move freely
Why are most metals malleable?
Layers of metal ions can slide over each other
Allows metals to be hammered or rolled into flat sheets
Describe the structure of a metal.
Giant structure of positive ions
Surrounded by a sea of delocalised electrons
