Bonding and properties of materials Flashcards
Covalent bonding
A covalent bond is a shared pair of electrons between atoms of two non-metal elements
What are the diatomic elements?
Bromine
Oxygen
Florine
Iodine
Nitrogen
Chlorine
Hydrogen
What are some examples of covalent networks
Boron, carbon and silicon are all examples of covalent network elements.
What an ionic bond?
Ionic bonds are formed between a metal and non-metal, for example sodium chloride
Ionic bonds attraction
The ionic bond is the electrostatic force of attraction between a positively charged metal ion and a negatively charged non-metal ion.
Metals form positive ions because they lose electrons to become stable.
Ionic compounds dissolve in water easily Wh
Ionic lattice info
All ionic compounds have a high melting point and boiling point because many strong ionic bonds need to be broken. They conduct when molten or in solution as the ions are free to move. They can be broken down by electrolysis. They are generally soluble in water
Covalent network info
All covalent network structures have very high melting points and boiling points because many strong covalent bonds need to be broken. They are all hard, and do not conduct electricity because there are no free charges that can move. They do not dissolve.
Covalent molecular info
They have low melting points and boiling points because the attractions between molecules are easy to overcome. They do not conduct electricity because there are no free charges to move. Some covalent molecular compounds have higher melting points than expected. Most do not dissolve in water but may dissolve in other solvents.
