Bonding, Structure and Properties of Matter Flashcards
Three properties that ionic compounds have:
- Conduct electricity when liquid
- High strength bonds
- High melting and boiling points
Hydroxide
OH-
Sulphate
SO₄²-
Nitrate
NO₃-
Carbonate
CO₃-²
Ammonium
NH₄+
Molecular formulae
The molecular formula of a substance shows the actual number of atoms of each element present in a compound or molecule.
Empirical formulae
The empirical formula of a substance is the simplest, whole number ratio of atoms of each element in a compound. This means that it doesn’t tell you exactly how many atoms there are, just the ratio of the atoms of each element.
Simple Molecules
- A simple molecule has multiple atoms covalently bonded together. These covalent bonds between atoms are very strong.
- However, the forces of attraction between separate molecules are weak, and so simple molecules are easily separated from each other.
Chlorine is a…
gas at room temperature.
Bromine is a…
liquid at room temperature.
Iodine is a…
solid at room temperature and gives off purple fumes.
Properties of simple molecular substances:
- Strong covalent bonds between the atoms of each molecule.
- Weak intermolecular forces between molecules.
- Low melting and boiling points (so normally gaseous as room temperature).
- Cannot conduct electricity.
Summary of giant covalent structures:
- Every atom is connected by strong covalent bonds
- No weak intermolecular forces as there is only one structure
- High melting and boiling points
- Cannot conduct electricity (except graphite)
Two substances made from the same element, that are in the same physical state, but that have different structures, are called…
Allotropes
