Human Biology 101: Chemistry of Life - Chemical Bonds, Ionic, Covalent, Hydrogen

Concept Summary

• Chemical bonds are the attractive and repulsive forces between atoms that hold them together in a molecule.
• There are three main types of chemical bonds: ionic, covalent, and hydrogen bonds.
• Ionic bonds form between a metal and a nonmetal, resulting in the transfer of electrons.
• Covalent bonds form between nonmetals, where electrons are shared between atoms.
• Hydrogen bonds are a type of intermolecular force that occurs between molecules with a hydrogen atom bonded to a highly electronegative atom.

Questions

WHAT (definitional)

1. What is an ionic bond?
2. Answer: An ionic bond is a type of chemical bond that forms between a metal and a nonmetal, resulting in the transfer of electrons.
3. Real-world example: The bond between sodium (Na) and chlorine (Cl) in table salt (NaCl) is an example of an ionic bond.
4. Misconception cleared: Ionic bonds do not involve the sharing of electrons, but rather the transfer of electrons from one atom to another.
5. What is a covalent bond?
6. Answer: A covalent bond is a type of chemical bond that forms between nonmetals, where electrons are shared between atoms.
7. Real-world example: The bond between two hydrogen atoms in a hydrogen molecule (H2) is an example of a covalent bond.
8. Misconception cleared: Covalent bonds involve the sharing of electrons, not the transfer of electrons.
9. What is a hydrogen bond?
10. Answer: A hydrogen bond is a type of intermolecular force that occurs between molecules with a hydrogen atom bonded to a highly electronegative atom.
11. Real-world example: The bond between water molecules (H2O) is an example of a hydrogen bond.
12. Misconception cleared: Hydrogen bonds are not a type of chemical bond, but rather a type of intermolecular force.

WHY (causal reasoning)

1. Why do ionic bonds form between a metal and a nonmetal?
2. Answer: Ionic bonds form between a metal and a nonmetal because the metal has a tendency to lose electrons, while the nonmetal has a tendency to gain electrons.
3. Real-world example: The formation of ionic bonds between sodium (Na) and chlorine (Cl) is an example of this process.
4. Misconception cleared: Ionic bonds do not form because of a difference in electronegativity, but rather because of a difference in electron affinity.
5. Why do covalent bonds form between nonmetals?
6. Answer: Covalent bonds form between nonmetals because they have a similar tendency to gain or lose electrons, resulting in the sharing of electrons.
7. Real-world example: The formation of covalent bonds between two hydrogen atoms in a hydrogen molecule (H2) is an example of this process.
8. Misconception cleared: Covalent bonds do not form because of a difference in electronegativity, but rather because of a similar electron affinity.
9. Why do hydrogen bonds form between molecules with a hydrogen atom bonded to a highly electronegative atom?
10. Answer: Hydrogen bonds form between molecules with a hydrogen atom bonded to a highly electronegative atom because the electronegative atom pulls the shared electrons closer to itself, resulting in a partial positive charge on the hydrogen atom.
11. Real-world example: The formation of hydrogen bonds between water molecules (H2O) is an example of this process.
12. Misconception cleared: Hydrogen bonds do not form because of a difference in electronegativity, but rather because of the partial positive charge on the hydrogen atom.

HOW (process/application)

1. How do ionic bonds form between a metal and a nonmetal?
2. Answer: Ionic bonds form between a metal and a nonmetal through the transfer of electrons, resulting in the formation of ions with opposite charges.
3. Real-world example: The formation of ionic bonds between sodium (Na) and chlorine (Cl) is an example of this process.
4. Misconception cleared: Ionic bonds do not form through the sharing of electrons, but rather through the transfer of electrons.
5. How do covalent bonds form between nonmetals?
6. Answer: Covalent bonds form between nonmetals through the sharing of electrons, resulting in the formation of a molecule.
7. Real-world example: The formation of covalent bonds between two hydrogen atoms in a hydrogen molecule (H2) is an example of this process.
8. Misconception cleared: Covalent bonds do not form through the transfer of electrons, but rather through the sharing of electrons.
9. How do hydrogen bonds form between molecules with a hydrogen atom bonded to a highly electronegative atom?
10. Answer: Hydrogen bonds form between molecules with a hydrogen atom bonded to a highly electronegative atom through the partial positive charge on the hydrogen atom.
11. Real-world example: The formation of hydrogen bonds between water molecules (H2O) is an example of this process.
12. Misconception cleared: Hydrogen bonds do not form through the transfer of electrons, but rather through the partial positive charge on the hydrogen atom.

CAN (possibility/conditions)

1. Can ionic bonds form between two nonmetals?
2. Answer: No, ionic bonds cannot form between two nonmetals because they do not have a tendency to transfer electrons.
3. Real-world example: The bond between two oxygen atoms in an oxygen molecule (O2) is an example of a covalent bond, not an ionic bond.
4. Misconception cleared: Ionic bonds require the transfer of electrons, which is not possible between two nonmetals.
5. Can covalent bonds form between a metal and a nonmetal?
6. Answer: Yes, covalent bonds can form between a metal and a nonmetal, but it is less common than ionic bonds.
7. Real-world example: The bond between zinc (Zn) and sulfur (S) is an example of a covalent bond.
8. Misconception cleared: Covalent bonds can form between metals and nonmetals, but it is not as common as ionic bonds.
9. Can hydrogen bonds form between molecules with a hydrogen atom bonded to a metal atom?
10. Answer: No, hydrogen bonds cannot form between molecules with a hydrogen atom bonded to a metal atom because the metal atom does not have a high electronegativity.
11. Real-world example: The bond between water molecules (H2O) is an example of a hydrogen bond, not between a molecule with a hydrogen atom bonded to a metal atom.
12. Misconception cleared: Hydrogen bonds require a highly electronegative atom, which is not present in metal atoms.

TRUE/FALSE (misconception testing)

1. Statement: Ionic bonds form between two nonmetals.
2. Answer: FALSE
3. Real-world example: The bond between two oxygen atoms in an oxygen molecule (O2) is an example of a covalent bond, not an ionic bond.
4. Misconception cleared: Ionic bonds require the transfer of electrons, which is not possible between two nonmetals.
5. Statement: Covalent bonds form between a metal and a nonmetal.
6. Answer: TRUE
7. Real-world example: The bond between zinc (Zn) and sulfur (S) is an example of a covalent bond.
8. Misconception cleared: Covalent bonds can form between metals and nonmetals, but it is not as common as ionic bonds.
9. Statement: Hydrogen bonds form between molecules with a hydrogen atom bonded to a metal atom.
10. Answer: FALSE
11. Real-world example: The bond between water molecules (H2O) is an example of a hydrogen bond, not between a molecule with a hydrogen atom bonded to a metal atom.
12. Misconception cleared: Hydrogen bonds require a highly electronegative atom, which is not present in metal atoms.