Which of the following is an example that includes evidence of a chemical reaction? a. A sample of zinc is placed in water and it settles to the bottom
b. A solid block of ice is heated and it completely melts into a liquid.
c. Sugar that is burned gives off an odor and turns brown and then black.
d. A tomato is chopped up into smaller pieces.

true

explanation:

"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."

the correct answer is:

a. formation of precipitation

um i think it might be a car?