Explanation:
For solid it could be melting into a liquid
for gas it could be Evaporating into a liquid
Mutations are spontaneous and occur at random however there are some mutagenic agents which increase the chance of this happening such as radiation exposure. If it is a point shift mutation then only a few bases on the dna sequence are changed so only changes a few of the amino acids in that chain (such as inversion of a base). If its a frame shift then the base sequence is altered so much so that every amino acid from after that changes (such as deletion of a base) which can create things such as cri-du-chat syndrome which results from a piece of chromosome 5 is missing. Hope this helps:)
I'm sorry its A..I didn't read it correctly...
