Methane is another substance that has covalent bonding between the elements that make it up. Each methane molecule has four hydrogen atoms covalently bonded to a carbon atom.
z Fig. 14.3.7
How electrons are shared by hydrogen and carbon atoms to form methane
14.3
Hydrogen atoms
Carbon atom
Methane CH4 Investigating the properties of ionic and covalent compounds
Copy and complete the table for the substances listed to identify each substance as an ionic or covalent compound: sugar, urea, washing soda crystal, table salt and benzoic acid.
1. Research the melting point of each compound. 2. Plan how you will test if each substance will conduct electricity. 3. Did your predicted bond type match up with the actual bond type? If not, explain why.
4. Each compound listed is found in everyday substances around the home. List an everyday substance that contains the compounds you tested.
Name of substance being tested
Sugar Properties of Ionic and Covalent Substances
The properties of ionic and covalent substances are usually the opposite of each other. The table below lists the properties of ionic and covalent substances.
Ionic substances Usually solids
Have high melting points and boiling points
Conduct electricity in liquid form or if they dissolve in water
Covalent substances Usually liquids or gases
Have low melting points and boiling points
Do not conduct electricity
Properties of materials are determined by the bonding that holds that material together.
247 State at room temperature
Melting point
Does it conduct electricity?
Predicted bond (based on
collected data)
Actual bond (based on verifying data from a reliable source)
