Covalent Bonding

Which of the following statements correctly describe covalent bonding?

• It involves the complete transfer of electrons from one atom to another

• It occurs primarily between metal and non-metal atoms

• It involves the sharing of electron pairs between atoms

• It always results in molecules with polar bonds

Answer explanation

Which of the following molecules contain a double bond?

• H₂ (hydrogen)

• NH₃ (ammonia)

• C₂H₄ (ethene)

• CO₂ (carbon dioxide)

Select the molecules that have a triple bond in their structure:

• N₂ (nitrogen)

• HCl (hydrogen chloride)

• H₂O (water)

• C₂H₂ (acetylene)

Which of the following compounds demonstrate octet expansion?

• PCl₅ (phosphorus pentachloride)

• NH₃ (ammonia)

• CH₄ (methane)

• SF₆ (sulfur hexafluoride)

Which characteristics apply to covalent compounds?

• Typically form crystals at room temperature

• Usually conduct electricity when dissolved in water

• Often exist as gases or liquids at room temperature

• Form discrete molecules rather than lattice structures

Which elements can expand their octet when forming chemical compounds?

• Chlorine (Z=17)

• Sulfur (Z=16)

• Nitrogen (Z=7)

• Carbon (Z=6)

In the molecule C₂H₆ (ethane), which statements are true?

• It contains seven covalent bonds

• The carbon atoms are connected by a double bond

• Each carbon atom forms four single bonds

• It contains a total of 8 atoms

Which of the following statements about PCl₅ (phosphorus pentachloride) are correct?

• It contains only single covalent bonds

• It can decompose to form PCl₃ under certain conditions

• The phosphorus atom obeys the octet rule

• The phosphorus atom shares 5 pairs of electrons

Which molecules contain only single covalent bonds?

• H₂ (hydrogen)

• NH₃ (ammonia)

• CH₄ (methane)

• HCl (hydrogen chloride)

Which of the following statements about covalent bonds is INCORRECT?

• They typically form between non-metal atoms

• They have higher melting and boiling points than ionic compounds

• They involve the sharing of electrons

• They result in the formation of stable molecules