Chemical Bonds

In chemical compounds, covalent bonds form when

• the electronegativity difference between two atoms is very large.
• electrons are completely transferred between two metals.
• pairs of electrons are shared between two nonmetal atoms.
• two nonmetal atoms are attracted to each other by opposite charges.

Which of the following is an example of an IONIC COMPOUND?

• NaCl
• H₂O
• CO₂
• NO

Which of the following is an example of a COVALENT COMPOUND?

• H₂S
• KI
• CaCl₂
• MgO

What do atoms that form positive ions tend to do?

• tend to lose electrons

• tend to lose protons

• tend to gain electrons

• tend to gain protons

Which of the following is NOT a property of ionic compounds?

• They conduct electricity when molten

• They conduct electricity when in solution

• They have high boiling points

• They are insoluble in water

How do ionic bonds affect the physical properties of ionic compounds?

• They make ionic compounds highly volatile.

• They give ionic compounds high melting and boiling points due to strong attractions between ions.

• They result in ionic compounds being soft and malleable.

• They cause ionic compounds to have low solubility in water.

Why do ionic compounds conduct electricity in a liquid state but not in a solid state?

• In a liquid state, ions are free to move and carry charge, whereas in a solid state, ions are fixed in place.

• Ionic compounds always conduct electricity regardless of their state.

• The ions in ionic compounds are neutralized in a solid state.

• Ionic compounds do not conduct electricity in either state.

Which statement is true about the electrical conductivity of covalent compounds?

• Covalent compounds conduct electricity well in both solid and liquid states.

• Covalent compounds do not conduct electricity in any state.

• Covalent compounds conduct electricity in the solid state but not in the liquid state.

• Covalent compounds conduct electricity in the liquid state but not in the solid state.

Which of the following is NOT a property of metals?

• Hard

• Can conduct electricity

• Very brittle (breaks easily)

• Malleable (can bend without breaking)

What do electrons do in a metallic bond?

• They stay on the metal atom.

• They are transferred from atom to atom.

• They form a covalent bond with another atom.

• They float around freely.