"High temperatures make the gas molecules move more quickly" is the one sentence among all the choices given in the question that most likely explains why this reaction is carried out at high temperature. The correct option among all the options that are given in the question is the third option or option "C".
Hope this helps :) remember your conversions and just practice it's fairly easy:)
Hey there!
The correct answer to your question is a compound.
A substance of two or more elements chemically combined in a set ratio, or proportion, is called a compound.
This is because compounds are made of two or more elements. Table salt is an example of a compound because it is made up of the elements chlorine and sodium.
Hope this helps you.
Have a great day!