Simple Molecular Substances Flashcards
What are the simple molecular substances made of?
Simple molecular substances are made up of molecules containing a few atoms joined together by covalent bonds.
Explain the molecular substances of hydrogen (H₂).
Hydrogen atoms have just one electrons. They only need one more to complete the first shell so they often form single covalent bonds, either with other hydrogen atoms or with other elements, to achieve this.
Explain the molecular substances of chlorine (Cl₂).
Each chloride tom needs just one more electron to complete the outer shell so two chorine atoms can share one pair of electrons and form a single covalent bond.
Explain the molecular substances of oxygen (O₂).
Each oxygen atom needs two more electrons to complete its outer shell so in oxygen gas two oxygen atoms share two pairs of electrons with each other making a double covalent bond.
Explain the molecular substances of nitrogen (N₂).
Nitrogen atoms need three more electrons so two nitrogen atoms share three pairs of electrons to fill their outer shells. This creates a triple bond.
Explain the molecular substances of methane (CH₄).
Carbon has four outer electrons, which is half a full shell. It can form four covalent bonds with hydrogen atoms to fill up its outer shell.
Explain the molecular substances of water (H₂O).
In water molecules, the oxygen shares a pair of electrons with two H atoms to form two single covalent bonds.
Explain the molecular substances of hydrogen chloride (HCl).
This is very similar to H₂ and Cl₂. Again, both atoms only need one more electron to complete their outer shells.
What are the atom within the molecules held by?
The atoms within the molecules are held together by very strong covalent bonds. By contrast, the forces of attraction between these molecules are very weak.
