<h2>Answer:</h2>
Compound. Option A is correct
<h2>Explanations:</h2>
When two or more different elements combines, a compound is formed. For instance, if carbon and oxygen combines, carbondioxide is formed according to the equation;

From the reaction, carbon and oxygen are the elements while carbondioxide is the compound. Hence we can conclude that a pure substance formed when two or more different elements combine called compound.
Answer:
Option (D)
Explanation:
<u>Eskers are the long ridges that are comprised of rocks, sands and clay particles and are deposited towards the end of the glaciers</u>. These are fluvioglacial depositional features. These particles are exposed after the glaciers recede. These ridges are formed parallel to the earlier flow direction of ice. The size of eskers is generally smaller as it carries smaller particles such as rocks, sands, and gravels, in comparison to the different type of moraines. It is because the flow velocity decreases as the glaciers melt. So, these eskers are formed at the end of the glaciers.
Thus, the correct answer is option (D).
<span>True. Acid rain is formed when compounds released during the burning of fossil fuels, such as sulfur dioxide and nitrous oxide, dissolve in water droplets in clouds. These then fall as rain as part of the water cycle. While some rain is naturally acidic, human activities, like burning fossil fuels, have made it worse.</span>
Answer:
E. HCl
Explanation:
Cl atom does not have enough electronegativity to make enough positive charge on H.
Answer:
The thermodynamic parameter which is of significance in this case is the 'Reduction Potential' for molecular bromine which is ~ +1.1 v vs N.H.E. In other words, it is a strong oxidizing agent. The bromine will oxidize sulfur compounds in which the valence of sulfur is lower than six to sulfate.
There are many possible reactions. Here is one possible example:
Na2 S2O3 + 4Br2 + 5 H2O = 2NaHSO4 + 8 HBr