There should be 2 since there’s 2 D atoms in the reaction.
If you really keep an eye on the flow chart, the only ions you can consider as being "Definitely not present" are: Cr3+, Fe3+, and Zn2+. The rest of the ions should be considered under "Possibly present", as we cannot conclude if any of the ions are "Definitely present".
Answer:
substance
Explanation:
A mixture is when two or more <u>different</u> atoms/molecules are together, but not joined.
A substance is when the <u>same </u>atom/molecule is in a group together.
In this example, it is a substance because it is comprised of the same molecule not joined all together. If you wanted a mixture, other colored atoms/molecule (e.g. add green atoms) would change it to this property.
Looking at a ph level color chart, it should be moving to more acidic if it’s positive