0.01742919 is the answer because i worked it out
Ionic compounds are formed between oppositely charged ions.
A binary ionic compound is composed of ions of two different elements - one of which is a positive ion(metal), and the other is negative ion (nonmetal).
To write the empirical formula of binary ionic compound we must remember that one ion should be positive and other ion should be negative, then only the correct formula should be written. To write the empirical formula the charges of opposite ions should be criss-crossed.
First empirical formula of binary ionic compound is written between
First Formula would be 
Second empirical formula is between 
Second Formula would be 
Note : When the subscript are same they get cancel out, so
would be written as 
Third empirical formula is between 
Third Formula would be :
Forth empirical formula is between 
Forth Formula would be :
or 
Note- The subscript will be simplified and the formula will be written as
.
The empirical formula of four binary ionic compounds are : 
Answer:
D. Many, many years of deposition
Explanation:
The layers of the rocks in one region of the parks are smooth and distinct, which are evidence of many, many years of deposition.
The layers on the rocks are because of different deposition of sediments. Different sediments deposited over the rocks through wind, water and ice over the ages.
Hence, the correct answer is D.