We have remember that lattice energy increases as the size of the ions in the ionic solid decreases. According to Oxford dictionary; lattice energy is "a measure of the energy contained in the crystal lattice of a compound, equal to the energy that would be released if the component ions were brought together from infinity."
We know that the larger the magnitude of charge on a cation the smaller in size the cation is and the size of anions increase from left to right in the periodic table. Hence Ca^2+<Na^+ and O^2- < Cl^-. Therefore the lattice energy of CaO is greater than that of NaCl.
It comes from the chemical reaction of The wax and the gas because the wax is made up of carbon-based chemicals so the gas and carbon make the candle light =)
The correct answer to this question is letter "A. homogeneous mixture." The following characteristics describe the type of mixture, which is a homogeneous mixture. The substance is mixed uniformly throughout and each part of <span>the substance contains the same ratio of materials with the same properties</span>