Technician A says that water floats to the top of fuel in the tank. Technician B says that water is more likely to be drawn into the system when the fuel level is low. Which technician is correct?

Of course, technician B is the smarter one!    

Explanation:

Water molecules attract each other, and the oil molecules also stick together. That causes oil and water to form two separate layers.

Because water molecules are denser than oil, they sink to the bottom, leaving oil sitting on top of the water.

Now, many fuel systems are designed in such a way that the suction pipe is located at the base of the tank. Given the above, it is very easy to see why water to a great degree of probability will be drawn into the system when the fuel level is low.

Cheers!

"among the transition metal elements, manganese and zinc have a slight lowering of electronegativities. the reason behind this is that the nuclear charges of these elements are slightly weaker than the other transition metal elements due to the way their valence electrons are filled up. both manganese and zinc have their valence electrons filled up to the 4th shell with 1 pair of electrons (4s2) completely occupying it. although the electrons in the 3rd shell (3d) are yet to be paired since the outer most shell is filled up, the ability of the nucleus to attract electrons is lessened. hence,   the electronegativity (or the ability to attract electrons) is lessened."