The principal ingredient of glass is quartz sand (SiO₂).
Do DIMENSIONAL Analysis what comes up must come down
The ice structure takes up more volume than the liquid water molecules, hence ice is less dense than liquid water. What is the exact change in volume of the water when it freezes as ice? Example: Calculate the volume in a 100 g ice cube with a density of 0.92 g per mL.
Answer:
Aluminum
Explanation:
Mass of 
= 1.68 g
Molar mass of = 143.32 g/mol
Thus,
From the reaction below:
3 moles of are produced when 1 mole of 
undergoes reaction.
So,
1 mole of are produced when 
mole of undergoes reaction.
0.01172 mole of are produced when 
mole of undergoes reaction.
Thus, moles of = 0.0039 moles
Let the atomic mass of X = x g/mol
atomic mass of chlorine = 35.5 g/mol
Thus, Molar mass of = x + 3(35.5) g/mol = x + 106.5 g/mol
Moles = 0.0039 moles
Mass = 0.521 g
Thus, molar mass = Given mass/ Moles = 0.521 / 0.0039 = 133.5897 g/mol
So,
x + 106.5 = 133.5897
x = 27.0897 g/mol
This Atomic weight corresponds to Aluminum. Hence, X is aluminum.
