Can a substance contract on heating?

The blue colour of crystals of a substance changed on heating in a closed test tube but the colour was regained after some time on cooling. Name the substance and write its chemical formula. Explain the phenomenon involved.

Explain the initiation of muscle contraction. What is the role of sarcoplasmic reticulum, myosin head and F-actin during contraction of striated muscles?

Assertion (A) : Antiferromagnetic substances on heating to high temperature become paramagnetic. Reason (R ) : On heating, the randomization of spins occurs.

Can we use any substance as photoelectron emitter?

What is Lanthanide contraction ? What is the cause and consequences of Lanthanide contraction ?

Name a substance which can act as non-narcotic analgesic.