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.
Answer:
im pretty sure its groundwater just read this and see the answer
Explanation:
The ocean holds about 97 percent of the Earth's water; the remaining three percent is found in glaciers and ice, below the ground, in rivers and lakes. Of the world's total water supply of about 332 million cubic miles of water, about 97 percent is found in the ocean.
Answer:
Adding Catalyst can Speed up a Chemical reaction
Allotropes are elements on the periodic table that have more than one crystalline form . There are three forms of the element carbon : Diamond, Graphite, and Fullerenes. Isotopes are atoms of the same element with the same atomic number but have a different mass number.
Answer:
well, through the process of cellular respiration, the energy in food is converted into energy that can be used by the body's cells. During cellular respiration, glucose and oxygen are converted into carbon dioxide and water, and the energy is transferred to ATP