Answer:
his experiment can show the movement of pollutants through the groundwater!
Explanation:
C. Solid
Although molarity is commonly used to express concentrations for reactions in solution or for titrations, it does have one drawback—molarity is the number of moles of solute divided by the volume of the solution, and the volume of a solution depends on its density, which is a function of temperature.
Answer: The solution to the problem expressed to he correct number of significant figures is 1.69
Explanation:
Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.
The rule applied for multiplication and division is :
The least precise number determines the number of significant figures in the answer.
As 12.0 has 3 significant digits and 7.11 also has 3 significant digits, the answer would also contain 3 significant digits.
For 
Thus the solution to the problem expressed to he correct number of significant figures is 1.69
It would take 4 years to reach earth