D - for example, Potassium has 1 electron on its outer shell, whilst Chlorine has 7 electrons on its outer shell. Potassium loses one electron to Chlorine so that each of them have a full outer shell. This would form Potassium Chloride.
Water is an essential part of life and its availability is important for all living creatures. On the other side, the world is suffering from a major problem of drinking water. There are several gases, microorganisms and other toxins (chemicals and heavy metals) added into water during rain, flowing water, etc. which is responsible for water pollution. This review article describes various applications of nanomaterial in removing different types of impurities from polluted water. There are various kinds of nanomaterials, which carried huge potential to treat polluted water (containing metal toxin substance, different organic and inorganic impurities) very effectively due to their unique properties like greater surface area, able to work at low concentration, etc. The nanostructured catalytic membranes, nanosorbents and nanophotocatalyst based approaches to remove pollutants from wastewater are eco-friendly and efficient, but they require more energy, more investment in order to purify the wastewater. There are many challenges and issues of wastewater treatment. Some precautions are also required to keep away from ecological and health issues. New modern equipment for wastewater treatment should be flexible, low cost and efficient for the commercialization purpose.
By stirring and increasing temperature, there is an increase in dissolving capacity of the solid solute.
<u>Explanation:</u>
If a solute is added to the solution, it doesn't get dissolve easily then we have to increase the temperature, which in turn increases the movement of the solvent (may be water) and the solute particles, thus increases the dissolving power of the solid solute. One more way is by constant stirring, that is by making more contact among the solvent as well as the solute particles there by increasing the solubility of solid solute.
Answer : The 
must be administered.
Solution :
As we are given that a vial containing radioactive selenium-75 has an activity of 
.
As, 3.0 mCi radioactive selenium-75 present in 1 ml
So, 2.6 mCi radioactive selenium-75 present in 
Conversion :
Therefore, the must be administered.
