Answer:
There are 8Si atoms and 16 O atoms per unit cell
Explanation:
From the question we are told that:
Edge length 
Density 
Generally the equation for Volume is mathematically given by



Where
Molar mass of (SiO2) for one formula unit


Therefore
Density of Si per unit length is


Molar mass of (SiO2) for one formula unit


Therefore
There are 8Si atoms and 16 O atoms per unit cell
i hope it help you a lot tell it is correct or not
Your answer is B: The outer electron of Adam B has moved to a higher energy state
Answer:
The advantages of using an indicator to inform pH measurements:
It gives a mathematically result of the pH, in addition, it gives the precise pH of solvent, and it also gives an idea of the straight of the solution also.
Now, the advantage of using a pH meter:
It is a rapid method to characterize between acids, bases. However, this method does not show how strong acid or base actually are, plus it tends to gives a range of acidity or basicity not quite accurate as a result.