Metals have characteristic physical properties. Which of the following statements are generally true for most metals: I. They are ductile, II. They are malleable, III. They are poor conductors of heat?

Introduction / Context:
In basic chemistry and physics, metals are described using a set of characteristic physical properties that distinguish them from nonmetals and metalloids. These properties include ductility, malleability, lustre, and good electrical and thermal conductivity. Exam questions often present several such statements and ask which are generally true for metals. This question lists three statements about metals and asks you to identify the correct combination based on standard textbook descriptions.

Given Data / Assumptions:

• Statement I: Metals are ductile, meaning they can be drawn into wires.
• Statement II: Metals are malleable, meaning they can be hammered into thin sheets.
• Statement III: Metals are poor conductors of heat.
• We consider typical metals under normal conditions, ignoring rare exceptions.

Concept / Approach:
Metals are usually both ductile and malleable due to the nature of metallic bonding, where positive metal ions are surrounded by a sea of delocalised electrons that allow layers of atoms to slide over each other without breaking the bond network. This gives metals the ability to be drawn into wires and hammered into sheets. Metals are also generally good conductors of heat and electricity because the delocalised electrons can move freely and transfer energy efficiently. Therefore, statements I and II are correct for metals, but statement III is the opposite of the truth. Metals are good, not poor, conductors of heat. The correct combination is that only I and II are generally true.

Step-by-Step Solution:
Step 1: Evaluate statement I: Metals can usually be drawn into thin wires. This property is called ductility and is a standard metallic characteristic. Step 2: Evaluate statement II: Metals can generally be hammered into thin sheets without breaking. This property is called malleability and also describes typical metals. Step 3: Evaluate statement III: Metals are poor conductors of heat. This contradicts the well known fact that metals are usually good conductors of heat due to mobile electrons. Step 4: Conclude that statements I and II are correct, while statement III is incorrect. Step 5: Match this conclusion with the options and select the one that states only I and II are generally true for metals.

Verification / Alternative check:
Every introductory chemistry textbook lists good thermal and electrical conductivity as key properties of metals. Copper pots, aluminium pans, and metal heat sinks demonstrate this in everyday life, as they transfer heat quickly. Ductility and malleability are also emphasised, with examples such as copper wires, gold jewellery, and aluminium foil. These real world examples show that statements I and II match common metallic behaviours, while statement III directly contradicts observable facts about metal thermal conductivity. This confirms the correctness of selecting I and II only.

Why Other Options Are Wrong:
The option that includes I and III wrongly suggests that metals are poor conductors of heat, which is false. The option with II and III also repeats the incorrect idea that metals are poor conductors. The option claiming that all three statements are true incorrectly treats poor thermal conductivity as a metallic property. Since statement III is wrong, any option that includes it as true must be rejected. Only the option stating that I and II are correct fits the known properties of metals.

Common Pitfalls:
Some students may misread statement III or confuse thermal conductivity with some other property, especially if they have encountered materials like wood or plastic, which are poor conductors and sometimes associated loosely with everyday objects. Another pitfall is to assume that if some metals have low conductivity compared with others, metals as a class might be poor conductors. To avoid these errors, remember that metals as a group are defined by their ability to conduct heat and electricity well, and that ductility and malleability are two other hallmark properties. With this in mind, it becomes easy to identify which statements are correct in exam questions.

Final Answer:
For most metals, only I and II are generally true for metals, meaning that they are ductile and malleable but good, not poor, conductors of heat.