chapter 4 Flashcards
chemical bond
A chemical bond can be thought of as a joining of atoms by the interaction of electrons.
This interaction can be due to the donation or sharing of electrons between atoms
types of chemical bond
Ionic bonds: formed between metals & non metals
- Metallic bonds: formed between metals
- Covalent bonds: formed between non metals
ionic bonding
An ionic bond is a bond that forms when metallic atoms combine with non-metallic atoms to form an ionic lattice
Electron(s) are donated from the metal to the non-metal, forming cations and anions
The attraction which holds them together is called electrostatic attraction
Electrostatic attraction is very strong!
the ionic lattice
Ionic compounds have their atoms arranged in an ionic lattice.
The cations and anions are held together by super strong electrostatic attraction.
This lattice is directional due to the charged ions.
An ionic lattice is a 3D structure comprising of the anions and cations in a 3D grid.
The anions and cations are arranged in alternate order.
properties of ionic compounds
Brittle
Hard surface
Dissolves readily in water or other solvents
Conduct electricity but only in an aqueous state
High melting point
High boiling points
Why are ionic compounds brittle
The cations and anions are arranged in an alternating pattern for ultimate stability.
If stress or force is applied, the rows are pushed out of place so that the charges are now aligned. This makes the like charges too close together.
Since like charges repel, the lattice shatters!
electricity conductivity and ionic compounds
Delocalised (free moving) ions (cations and anions) enable current to flow
Electrostatic attraction with ionic compounds
the greater the charge o the ions, the greater the electrostatic attraction
Hydrated ionic compounds
Ionic compounds called hydrates produce water when they decompose or when they are heated.
