Transition metals are generally harder than poor metals, which tend to be relatively soft.

Key physical difference

  • Transition metals (like iron, nickel, and copper) are usually hard, tough, and have strong metallic bonding, giving them good mechanical strength.
  • Poor (post-transition) metals (like lead, tin, and indium) are typically softer, have poorer mechanical strength, and are easier to deform or cut.

So, if you need just one key physical difference for an exam-style question: transition metals are harder, while poor metals are comparatively soft.