Ineed some like right now this second so me if u don't know don't answer like for real
keri has to identify a mysterious brown liquid in science class. she pours it through a filter, but the substance looks the same. then she heats the substance and collects the water that evaporates. the water droplets look the same as the original substance. keri concludes that since the substance cannot be separated it must be a compound. is keri correct?
group of answer choices
a: yes because water is a compound.
b: no because the substance could be an element.
c: yes because keri tried to separate it and all mixtures can be separated physically.
d: no because compounds can be separated physically.

D: No because compounds can be separated physically.

Explanation:

Many substances are made up of more than one type of atom and for this reason we can call them compound or simply compound substances. A relatively small number of elements can yield numerous different compounds. Once a compound is formed, the substances that gave rise to it can be separated by some physical processes. Based on this, we can state that compounds are substances that can be physically separated, so we can conclude that Keri is incorrect.

"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."