A pure crystalline substance is a substance with an almost perfect regular and periodic pattern in a solid state. This makes this type of substance a hard one compared to an amorphous substance which is soft because of the irregular pattern within.
The answer is E.
Chemoautotrophs are organisms that use inorganic <span>compounds as an energy source and CO2 as a carbon source. The organisms live in </span>hostile environments like dark depths of the sea. Inorganic energy sources that they use are mostly hydrogen sulfide, elemental sulfur, ferrous iron, molecular hydrogen, and ammonia.
Answer:
2 HCl + CaCO3 = CaCl2 + H2O + CO2
Explanation:
On the right side we have 2xCl, to get the same amount we will multiply HCl on the left side by 2.
This will give us 2xH on the left side; we also have 2xH on the right side ( in H2O).
On both sides we have 1x Ca; 1x C.
On the left side we have 3XO (in CaCO3), on the right side we have 1O in H20 and 2xO in CO2, so 3x O on the right side as well.
The reaction is balanced.
Urban development has been linked to many environmental problems, including air pollution, water pollution, and loss of wildlife habitat. Urban runoff often contains nutrients, sediment and toxic contaminants, and can cause not only water pollution but also large variation in stream flow and temperatures.
The molecular formula of dimethyl sulfoxide is 
. Molar mass of dimethyl sulfoxide is 78.13 g/mol. Calculate number of moles as follows:
From the molecular formula, 1 mole of dimethyl sulfoxide contains 2 moles of Carbon, 6 moles of Hydrogen, 1 mole of Sulfur and 1 mole of oxygen.
Thus, 91.38 moles of dimethyl sulfoxide will have:
Carbon :
Hydrogen:
Sulfur:
Oxygen:
Since, 1 mole of an element equals to 
atoms thus, number of atoms can be calculated as:
Carbon:
Thus,
Hydrogen:
Thus,
Sulfur:
Thus,
Oxygen:
Thus,
Therefore, number of C, S, H and O atoms are 
respectively.
