Answer:
a)Atomic number
Explanation:
Element symbol signifies the element. For eg, Na is sodium. Mass number is the sum of protons and neutrons of an atom of an element. Atomic mass is the molar mass of the given element. Finally, atomic number is unique to each element because it signifies the number of protons of that element. EACH ELEMENT has their UNIQUE number of protons. For eg, atomic number of hydrogen is 1 because it has 1 proton, NO OTHER ELEMENT HAS ATOMIC NUMBER 1 because NO OTHER ELEMENT HAS 1 proton.
If the temperature of a liquid-vapor system at equilibrium increases, it will shift towards the vapor phase, assuming that the pressure remains equal. The concentration of vapor will also increase relative to the concentration of liquid in the system. Thus, the new equilibrium condition will have more vapor than liquid.
It's reported inside the riddles or decorations