Question

I need some one to write a passage

Answer 1

Part A is 2.5 x $10^{-5}$ because the decimal place has been moved five times to the left, which makes it negative. 

Part B is 
First, find what the diameters of both things are written out. 
1 x $10^{-5}$ = .00001
1 x $10^{-4}$ = .0001

Now find out how many times the size of a cell has to be multiplied to equal the diameter of a grain of sand. 

.00001 x 10 = .0001
.0001 = 1 x $10^{-5}$

So the diameter of a grain of sand is 10 times longer than the diameter of the average cell in the human body.