1. Curiosity
2.<span> Necessity</span>
Yes you are right .. X is undergoing a change from solid to gas at point E
To Find :
Number of moles of C₃H₆O present in a sample weighing 25.6 grams.
Solution :
Molecular mass of C₃H₆O is :
M = (6×12) + (6×1) + (16×1) grams
M = 94 grams/mol
We know, number of moles of 25.6 grams of C₃H₆O is :

Hence, this is the required solution.
Answer:
polymerization
Explanation:
Student is explaining the process of formation of a polymer and the process is called polymerization.
Polymer is made up of joining repeating units. The repeating units are called monomers.
Properties of the polymer is determined by the structure of monomer molecule.
For example, consider a well-known polymer Teflon.is made by the polymerization of tetrafluoroethane.
Thus, the student is explaining polymerization.
Answer:
However, various hydrogen isotopes, such as H-2, have one proton and one neutron; H-3 has one proton and two neutrons, etc. The sum of the protons and neutrons in an atom's nucleus is its atomic mass. Thus, the atomic mass of the H-2 isotope is two, the atomic mass of the H-3 isotope is three, and so forth.
Explanation: