Answer:
0.01744 M is the hardness of the groundwater.
1,744 ppm is the hardness of the groundwater in parts per million of calcium carbonate by mass.
Explanation:

In = Indicator
Concentration of calcium ion in groud water = 
Volume of ground water = 
Concentration of EDTA solution = 
Volume of EDTA solution = 



![[CaCO_3]=[Ca^{2+}]](https://tex.z-dn.net/?f=%5BCaCO_3%5D%3D%5BCa%5E%7B2%2B%7D%5D)
So. ![[CaCO_3]=0.01744 M](https://tex.z-dn.net/?f=%5BCaCO_3%5D%3D0.01744%20M)
0.01744 M is the hardness of the groundwater.
0.01744 Moles of calcium carbonate are present in 1 Liter of solution.
Mass of 0.01744 moles of calcium carbonate =

1 g = 1000 g
1.744 g = 1.744 × 1000 mg = 1,744 mg

The hardness of the groundwater in parts per million :

1,744 ppm is the hardness of the groundwater in parts per million of calcium carbonate by mass.
As the hurricane moves toward shore, the underwater tumult can cause shifting sands and muddy shallow waters, blocking the essential sunlight on which corals and other sea creatures rely. (Brainliest please)
Answer: 10 moles
To find how many moles, you need to divide the number of atoms with 6.02 * 10^23. Since every magnesium chloride has two chlorine atoms, you need to multiply it by 2. The calculation would be: 3.01×10^24 * 2 / 6.02 * 10^23= 10 moles
Each layer has a unique chemical composition, physical state, and can impact life on earths surface. Movement in the mantle caused by variations in heat from the core, causes the plates to shift, which can cause earthquakes and volcanic eruption‘s.
What you need to do is find 1/8 of 50
you can just divide 50 by 8 to get 6.25
so now you have to find how many days it will take till there are 6.25 grams of iodine left
every 8.1 days its mass is split in half
so start splitting it in half and every time you do, you add 8.1 days
50/2 =25 8.1
25/2 =12.5 + 8.1
12.5/2= 6.25 +8.1
now you have reached 1/8 of the original amount of Iodine-131
so to find how long it took just add 8.1+8.1+8.1
(this is the same as 8.1x3)
which equals 24.3
it will take 24.3 days for Iodine 131 to decay to 1/8 of its original mass.
(good luck on the regent if thats what your studying for :)