q1. coconut oil freezes in winters and liquefies in summers this example show what kind of phenomenon

q2. what is bulk phenomenon?

1. Coconut oil freezes in winters and liquefies in summers, this example shows the change in state of matter on the action of temperature. The phenomenon is known as freezing and melting respectively. 
2. https://www.meritnation.com/ask-answer/question/what-is-bulk-phenomenon/science/2172961