Understanding Covalent Bonds

What is the primary reason atoms form covalent bonds?

• To decrease their atomic number

• To increase their atomic mass

• To create oppositely charged ions

• To achieve a full outer shell by sharing electrons

In a dot and cross diagram, what do the dots and crosses represent?

• Protons and neutrons

• Molecular weight

• Electrons from different atoms

• Different types of atoms

What is a displayed formula used for?

• Calculating molecular weight

• Representing the chemical symbols and bonds in a molecule

• Identifying isotopes

• Showing the 3D shape of a molecule

How many hydrogen atoms are involved in the covalent bonding of ammonia?

• Three

• Four

• Two

• One

What is the maximum number of electrons the first energy level of hydrogen can hold?

• Four

• Two

• One

• Three

What is a limitation of displayed formulas?

• They do not show the 3D shape of molecules

• They are too complex to draw

• They are only used for ionic bonds

• They require knowledge of isotopes

What are simple molecular substances characterized by?

• Metallic bonds

• High melting points

• Weak intermolecular forces

• Strong intermolecular forces

What are polymers made of?

• Single atoms

• Repeating units called monomers

• Metallic elements

• Ionic compounds

Which of the following is an example of a giant covalent structure?

• Diamond

• Sodium chloride

• Methane

• Water

What is a common use for polymers?

• Making plastic bags

• Creating gemstones

• Building bridges

• Conducting electricity