Areaction occurs when solid x is placed into solution y. as a result, the temperature of the new solution increases by 3°c. the temperature rises another 2°c when more of solid x is added to the solution. what does this indicate about the effect of adding more solid?
a it increased the number of molecular collisions.
b it decreased the number of molecular collisions.
c it decreased the space between the molecules and lowered the reaction rate.
d it increased the space between the molecules and increased the reaction rate.

A. It increased the number of molecular collisions.

"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."