The answer is C. A, B, and C would depend on what type of electron it is.
Answer:
CaCO₃ built up in hot water pipes
Explanation:
The hardness of water is classified as;
Permanent Hard Water:
In this the mineral content cannot be removed by boiling. This water contains mainly following,
Calcium Sulfate CaSO₄
Calcium Chloride CaCl₂
Magnesium Sulfate MgSO₄
Magnesium Chloride MgCl₂
These salts does not precipitate out on heating water.
Temporary Hard Water:
In this water the mineral content can be removed by boiling. This water contains mainly following,
Calcium Bicarbonate Ca(HCO₃)₂
Calcium Carbonate CaCO₃
Magnesium Bicarbonate Mg(HCO₃)₂
Magnesium Carbonate MgCO₃
These salts does not precipitate out on heating water. i.e.
Ca(HCO₃)₂ -------heat------> CaCO₃ + CO₂ + H₂O
The CaCO₃ are formed in the form of scales.
Result:
Hence, we can say that that CaCO₃ built up in hot water pipes.
Answer:
The highest energy level number (1 through 7) for the electrons in an atom corresponds to the period (or row) in the periodic table to which that atom belongs. Because there are 7 periods in the table, there are 7 energy levels. For example, hydrogen (H) is in the first period, so it has only one energy level.
