The atomic mass of Cl2, which is the chemical formula for chlorine gas, is 70.906 g/mol. This value is calculated by adding the atomic mass of two chlorine atoms, which is 35.453 g/mol each. Therefore, the total atomic mass of Cl2 is 70.906 g/mol. **

The chemical formula for chlorine gas is Cl2 because chlorine exists as a diatomic molecule in its natural state. This means that two chlorine atoms bond together to form a stable molecule. Therefore, when referring to chlorine gas, it is denoted as Cl2 to indicate the presence of two chlorine atoms bonded together. **

Chlorine gas (Cl2) is commonly used in pools as a disinfectant to kill bacteria, viruses, and algae. It helps to maintain the cleanliness and safety of the pool water by preventing the growth of harmful microorganisms. The presence of Cl2 in the pool ensures that the water remains sanitary and suitable for swimming. Additionally, Cl2 helps to oxidize organic matter and other contaminants in the water, keeping it clear and free of unpleasant odors. **

Cl2, or chlorine gas, has a total of 14 valence electrons. Each chlorine atom contributes 7 valence electrons, and since there are two chlorine atoms in Cl2, the total number of valence electrons is 7 + 7 = 14. **

The concentration of NO3 and Cl2 being too high would depend on the specific context. In the case of drinking water, the maximum contaminant level for nitrate (NO3) is 10 mg/L, as higher levels can pose health risks, especially for infants. For chlorine (Cl2), the recommended concentration for disinfection in drinking water is typically around 0.2-4 mg/L, so levels significantly higher than this could be considered too high. It's important to consider the specific regulations and guidelines for each substance in the given context to determine if their concentrations are too high. **

The ionization of Cl2 occurs when one of the chlorine atoms in the molecule gains an electron, forming a negatively charged ion (Cl-). This ion then combines with another Cl- ion to form a Cl2- ion. This process occurs through the transfer of electrons, resulting in the formation of a negatively charged ion. **

Among the molecules N2, Cl2, H2O, and CH3OH, the molecule with the lowest boiling point is N2 (nitrogen gas). This is because N2 is a nonpolar molecule with only London dispersion forces between its molecules, which are weaker compared to the dipole-dipole and hydrogen bonding present in the other molecules. Therefore, N2 requires less energy to overcome these intermolecular forces and transition from a liquid to a gas, resulting in a lower boiling point. **

No, it is not normal for Cl2 (chlorine gas) to be present in a new aquarium. Chlorine is a common disinfectant used in tap water, but it is harmful to fish and other aquatic organisms. Before adding any fish or plants to the aquarium, it is important to dechlorinate the water using a water conditioner to remove chlorine and make the water safe for aquatic life. **