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 
What is horoscope?
A forecast of a person's future, typically including delineation of character and circumstances, based on the relative positions of the stars and planets at the time of that person's birth.
*A short forecast for people born under a particular sign, especially as published in a newspaper or magazine.
*A birth chart.
What is its uses?
It can also be calculated for an event, a question, and even a country. Symbols are used to represent planets, signs, and geometric connections called aspects. In most cases, the horoscope in Western astrology is drawn on a circular wheel.
Equilibrium force is the force that will keep the small
mass in place, hence no movement must be made. So we know that 32 N of force is
acted towards the positive direction so +32 N. Which is counteracted by 26 N
force so:
32 N – 26 N = 6 N (positive)
Since positive 6 is left, therefore this must be acted by
an equilibrant negative 6 N.
Answer:
<span>- 6 N </span>
Answer: 6.9x 107 in standard form is 69,000,000