Let's see. It's definitely not the O horizon, because that layer is at the very top. A is already eliminated. Same thing with the A horizon, that is actually the top soil. C is out. It has to be either B or D. A D layer doesn't exist, so B is out. But the B horizon is considered a region of subsoil. The answer is D: B horizon.
Answer:
Lowering activation energy of a reaction.
Explanation:
Activation energy is the minimum amount of energy required by the reactants just to be converted to products.
Since catalysts increase the rate of reaction, activation complex is reached in short period of time hence activation energy is lowered.
This can be explained by the periodic trend that atomic size decreases from left to right in a given period. This is due to the effective nuclear charge increase, or how much more the nucleus pulls in on the electrons. Therefore Sodium (Na) has the largest atomic radius.
Neutral water<span> has the same concentration of Hydrogen ions which are also called the H+ and the Hydroxide ions, which also could be referred to as OH-. A neutral water is considered to have a pH level of 7 wherein it stands between the acid level and the base level which makes it suitable for human consumption.</span>
Mn metal can be used as a sacrificial electrode to prevent the rusting of an iron pipe. So, the correct option is (c) Mn.
Commonly, sacrificial electrodes are employed to stop another metal from corroding or oxidising. A metal that is more reactive than the metal being shielded must serve as the sacrificial electrode. Magnesium, aluminium, and zinc are the three metals most frequently used in sacrificial anodes.
Manganese-Magnesium (Mn-Mg) electrode is more suited for on-shore pipelines where the electrolyte (soil or water) resistivity is higher since it has the highest negative electropotential of the three. In order to replenish any electrons that could have been lost during the oxidation of the shielded metal, the highly active metal offers its electrons.
Therefore, Mn metal can be used as a sacrificial electrode to prevent the rusting of an iron pipe. So, the correct option is (c) Mn.
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