Answer:
A) Sample B has more calcium carbonate molecules
Explanation:
M = Molar mass of calcium carbonate = 100.0869 g/mol
= Avogadro's number = 
For the 4.12 g sample
Moles of a substance is given by

Number of molecules is given by

For the 19.37 g sample

Number of molecules is given by


So, sample B has more calcium carbonate molecules.
The ratio of the elements of carbon, oxygen, calcium atoms, ions, has to be same in both the samples otherwise the samples cannot be considered as calcium carbonate. Same is applicable for impurities. If there are impurites then the sample cannot be considered as calcium carbonate.
A. 1,2,3. The solutions are getting lighter meaning the concentration is decreasing. Its most likely that water was added to dilute the solutions.
Answer:
Explanation:
Density is m/V. Also, 1 liter = 1000
. So, we get 0.890/(5*1000) =
g/cm^3. You can convert this to kg/m^3 as well by multiplying it by 10. Depends which one you want.
Just post the question on here
Answer:
Yes
Explanation:
Isotopes are atoms of the same element that have different numbers of neutrons in their nuclei. Everything else about them is the same.(If you want more explanation tell me).