Answer:
crystal structure
Explanation:
A crystal structure is an ordered arrangement of atoms,ions or molecules in a regular repeating pattern,it is a form of solid state of matter and differs from liquid and gaseous states of matte in which the atoms or molecules are random or haphazard.
Random errors will shift each measurement from its true value by a random amount and in a random direction. These will affect reliability (since they're random) but may not affect the overall accuracy of a result.
X

H has a positive 1 charge. This means that having 3H = +3<span>. This is a neutral compound so x= -3 because X+3H= 0
Y</span>

is also neutral so 2X+Y= 0
we know X=-3 So, 2(-3)+Y=0
-6+y=0
Y=+6 charge
Answer: The valency of X is -3.
The valency of Y is 6