Although coal and diamonds are both composed of carbons alone, they differ in their properties because of the bonds present in each substance. Diamonds are composed of covalent bonds which are strong and is crystalline in nature which makes it sturdier. Coal is amorphous which allows the slipping of irregular layers to each other making coal brittle
Not sure but i think living things adapt to their environment.
Adaptations are traits giving an organism an advantage in a certain environment. And variations of individuals is important for a healthy species. So i think adaptation might be the right answer because animal will try to adapt the certain environment. I hope this answer will help you.
When the collision of gas particles and the volume of the gas stay the same it causes a chemical.
They are kind of opposite processes. Chemical synthesis is execution of chemical reactions to make products. Like you take two substances, you put them together, they react and you have new a substance. For example.

here Sodium and Chlorine react to make a new substance which is Sodium Chloride.
Chemical decomposition is process of seperating a substance to different substances. There is a substance by a reaction this substance becomes two substances, Like : XY -> X+Y For example :