How bonding and structure are related to the properties of substances common mistakes

Common mistakes

• Misunderstanding Intermolecular Forces in Polymers

  Students often think that intermolecular forces in polymers are weak like those in small molecules.

  Fix itEmphasize that intermolecular forces between polymer molecules are relatively strong compared to many small molecules.

• Misunderstanding Polymer States

  Students often think that all polymers are liquids at room temperature.

  Fix itEmphasize that many polymers are solids at room temperature due to strong intermolecular forces between polymer molecules.

• Misunderstanding Giant Covalent Structures

  Students often describe giant covalent substances as having weak bonds between atoms.

  Fix itEmphasize that giant covalent substances are characterized by many strong covalent bonds linking the atoms together.

• Misunderstanding melting points

  Students often think that giant covalent structures have low melting points because they are made of non-metal atoms.

  Fix itEmphasize that giant covalent structures are held together by many strong covalent bonds, which require a lot of energy to break, resulting in very high melting points.

• Misunderstanding Bonding in Giant Covalent Structures

  Students often state that covalent bonds are broken when a giant covalent substance melts or boils.

  Fix itStudents should clarify that it is the strong covalent bonds that must be overcome, not broken, to change the state of the substance.

• Giant covalent structures correction for Misidentifying Giant Covalent

  Students often confuse diamond and graphite with small molecular substances due to their carbon composition This error matters in Giant covalent structures because it drifts away from the objective: Identify diamond, graphite and silicon dioxide as examples of giant covalent structures.

  Fix itCorrect it by naming the exact chemistry idea, using precise bonding or structure vocabulary, and linking the answer back to Giant covalent structures. For this objective, students should identify diamond, graphite and silicon dioxide as examples of giant covalent structures.

• Giant covalent structures correction for Misidentifying Structures.

  Students often confuse giant covalent structures with simple molecular substances when looking at diagrams, failing to recognize the extensive covalent bonding in giant structures This error matters in Giant covalent structures because it drifts away from the objective: Recognise giant covalent structures from diagrams showing bonding and structure.

  Fix itCorrect it by naming the exact chemistry idea, using precise bonding or structure vocabulary, and linking the answer back to Giant covalent structures. For this objective, students should recognise giant covalent structures from diagrams showing bonding and structure.

• Properties of metals and alloys correction for Misunderstanding Metall

  Students often think that metals have high melting and boiling points due to the size of the metal atoms rather than the strength of metallic bonding This error matters in Properties of metals and alloys because it drifts away from the objective: Explain why most metals have high melting points and high boiling points using strong metallic bonding.

  Fix itCorrect it by naming the exact chemistry idea, using precise bonding or structure vocabulary, and linking the answer back to Properties of metals and alloys. For this objective, students should explain why most metals have high melting points and high boiling points using strong metallic bonding.

• Misunderstanding Metal Structure

  Students often describe pure metals as having random arrangements of atoms instead of regular layers.

  Fix itEmphasize that pure metals have atoms arranged in regular layers, which allows them to slide over each other.

• Misunderstanding Metal Structure

  Students often think that the layers of atoms in pure metals cannot slide because they are tightly packed.

  Fix itEmphasize that the regular arrangement of atoms in pure metals allows layers to slide over each other, which is what enables metals to be bent and shaped.