ii)Transition metals and their compounds show catalytic activities because of Variable or multiple oxidation states, ability to form complexes, they provide large surface area for adsorption.

SinceECu2+/CuECu2+/Cuhas a greater positive value thanEH+/HEH+/H, the reaction that is feasible at the cathode is

Cu2+(aq)+2eCu(s)

Yes, if the angle between the two vectors is more than 90^o but less than 270⁰. (cosΘ is negative)

Water is a vital substance for life on Earth, and it plays numerous important biological roles in living organisms. Some of the key biological roles of water are:

1. Universal solvent: Water is an excellent solvent for many substances, both organic and inorganic. This means that it can dissolve and transport a wide range of nutrients and minerals necessary for the growth and survival of living organisms.

2. Medium for metabolic reactions: Many metabolic reactions in living organisms require water...

If one could be a billionaire by following a how-to guide step by step, you'd have already come across it by now. 

Well, the how-to "BE" part is simple; own anything that's worth a billion- an idea, an asset, a skill, anything. It is the how-to reach that milestone that is mystic. Carve your own path to it. 

Once you find the secret (IF there is one), share it on Mattrab :P 

Or maybe don't ;) let others find their own path.