Unit 1 - Bonding Flashcards
Which type of chemicals will contain metallic bonding?
Metals
Which type of chemicals will contain covalent bonding?
Non-Metals
Which type of chemicals will contain ionic bonding?
Metals and non-metals
What is an ionic bond?
Ionic bond is the electrostatic attraction between positive and negative ions.
What is meant by an ionic lattice?
A lattice is a regular arrangement of ions where each positive ion is surrounded by negative ions and each negative ion is surrounded by positive ions.
Explain the physical properties of ionic compounds:
melting point and boiling point
solubility (water molecules surround ions)
electrical conductivity
Ionic compounds have high melting and boiling points because strong ionic bonds must be broken in order to break down the lattice.
Tend to be soluble in water.
Ionic compounds conduct electricity only when molten or in solution.
What is a covalent bond?
In a covalent bond, the shared pair of electrons is attracted to the nuclei of the two bonded atoms.
Covalent bonds are usually between non metals.
What are the two types of covalent structures?
Covalent substances can form either molecular or network structures.
Which elements exist as diatomic molecules?
HOFBrINCl
Hydrogen, Oxygen, Fluorine, Bromine, Nitrogen, Chlorine. These elements also form the shape of the number 7 on the Periodic Table.
Name the shapes of molecules.
Linear
Angular (or bent)
Trigonal Pyramidal
Tetrahedral
Explain the physical properties of covalent molecular compounds:
melting point and boiling point
solubility (water)
electrical conductivity
Covalent molecular substances have low melting and boiling points as only weak forces of attraction between molecules are being broken.
Covalent molecules tend to be insoluble in water but soluble in covalent type solvents.
Covalent molecules never conduct except carbon graphite.
Explain the physical properties of covalent network compounds:
melting point and boiling point
solubility (water molecules surround ions)
electrical conductivity
Giant covalent network structures have very high melting and boiling points because the network of strong covalent bonds must be broken.
Covalent molecules tend to be insoluble in water but soluble in covalent type solvents.
Covalent molecules never conduct except carbon graphite.
Describe the bonding in metals.
In metallic bonding, the outer electrons are delocalised (free to move). This produces an electrostatic force of attraction between the positively charged metal ions, and the negatively charged delocalised electrons.
Explain the physical properties of metals.
Melting and boiling points
Conductivity of electricity
Metals are held together by strong forces and have high melting and boiling points.
The ability of metals to conduct electricity stems from their delocalised electrons. As these are free to move, an electrical current can flow through metallic materials.
