Phase Transitions, Order Parameters and Broken Symmetry · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Order appears, symmetry goes

Science · Thermal & Statistical Physics · ages 22-24
Name ______________________   Date ____________

  1. What is the order parameter of a magnet?

    • Volume
    • Magnetization
    • Temperature

  2. What appears in the free energy at a transition?

    • A kink: a derivative jumps or diverges
    • A flat minimum everywhere
    • Nothing at all

  3. A continuous transition grows its order parameter smoothly from zero with no latent heat.

    Circle one:   True   False

  4. A transition releases latent heat. Which kind is it?

    • Continuous
    • First-order
    • Neither kind

  5. A cold magnet points north. Which symmetry did its state give up?

    • Translation symmetry
    • Time reversal only
    • Rotation symmetry

  6. A sample sits deep in the disordered phase. What does its order parameter read?

    • Zero
    • Maximum
    • Undefined always

  7. A parameter grows smoothly from zero and no heat hides at the point. Which type?

    • First-order
    • Continuous
    • No transition at all

  8. A student says the laws lost rotation symmetry in a magnet. What is wrong?

    • Magnets have no symmetries at all
    • The laws keep it; the state gave it up
    • Symmetry cannot break spontaneously
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Answer key

For grown-ups. Fold this page away before handing over the rest.

Order appears, symmetry goes W1-mt_3DQjfNJ-Ef-s1

  1. Magnetization · It measures the picked alignment.
  2. A kink: a derivative jumps or diverges · Lost smoothness is the mathematical mark.
  3. True · Smooth growth is what continuous means.
  4. First-order · Latent heat rides the jump.
  5. Rotation symmetry · Picking a direction breaks rotation.
  6. Zero · No order means a zero reading.
  7. Continuous · Smooth plus heat-free spells continuous.
  8. The laws keep it; the state gave it up · Breaking lives in states, not laws.
Worksheet · LightMySky