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
Answer: for 3. I would say it means that the amplitude is greater because if a sound is louder that means the amplitude is larger, same with the light.So that would mean the softer the sound the smaller the amplitude same with the dim of the light so for 4. It would be the amplitude is smaller. Hope this helps! :) ( if you have any questions feel free to ask)
Answer:
25kJ
Explanation:
Given the initial energy to be 30kJ
The energy change from the initial energy to the peak energy = (65-30) kJ
= 35kJ
since the second energy change was a drop in energy it is regarded negative
= (55-65)
= -10kJ
Therefore total energy change
= (35-10)kJ
= 25kJ
Tell your teacher. They'll know what to do and it's best to report it to them.