Part a
Answer: 
For the arrangement considered in part a, all the atoms are aligned side by side along the side of the square surface.
Along one side of the square, the number of atoms that could fit 
This is along one side. On the entire surface:
Number of atoms 
Part b
Answer: 
consider the attached figure below:
The next layer of atoms are filled in the depressions of the first layer. The vertical distance between the two atoms would change. Consider an equilateral triangle drawn by joining the centers of the three atoms.
The atoms along the horizontal side would be aligned side by side; same as above 
The number of atoms along vertical side would vary. vertical distance between two atoms can be calculate using equilateral triangle as shown below.
an equilateral triangle has all the angles 
Let the vertical distance be y.
Then, 
where r is the radius of each atom. 

The number of atoms along the vertical side 
Total number of atoms in this kind of arrangement 
A can opener makes work easier by increasing force.
Explanation
Technically a can opener is a simple lever that increases the force with which we remove the cap of the can. Levers are rod shaped objects with fulcrum at one end and the length of the lever has a positive impact on the force.
considering the equation
work=force*distance
indicates that increasing the length of the lever/can opener increases the work done by it.
We have no way to say what the illustration represents, mainly because
you haven't given us a way to see the illustration.
<span>However, the process that all stars, including our sun, use to continuously
produce energy is nuclear fusion.</span>
Answer:
0.46km
Explanation:
45963cm/100cm=459.63m/1000m=0.45963 or 0.46km
E, there is no state of matter that has no particle motion, however a solid's particles are only vibrating.