Answer: C.) polyatomic anion
Explanation: Cations are the ions which carry a positive charge and anions are the ions which carry a negative charge. Monoatomic ions are those which consists atoms of similar elements and polyatomic ions are those which consists of atoms of different elements.
For example :
is a monoatomic cation.
is an monoatomic anion.
is a polyatomic cation.
is a polyatomic anion as it consists of atoms of phosphorous and oxygen and bears a negative charge.
Answer : Cadmium sulfide (CdS) precipitate is formed.
Explanation :
When the sodium sulfide,
is mixed with cadmium sulfate,
then cadmium sulfide precipitate and sodium sulfate,
is formed. The cadmium sulfide is insoluble in hot and cold water but sodium sulfate is soluble in water.
The balanced chemical reaction will be,

This reaction is an example of double displacement reaction in which the cation and anion of the two reactants exchange their places to give two new products.
This is a chemical reaction where the two clear solutions mixed to produce a bright yellow colored precipitate of cadmium sulfide.
Answer:
Other: How does the temperature at which plants are grown affect plant growth?
Explanation:
The only variable in the table that isn't a constant is the temperature at which the plants were grown. This means that the scientists planted the groups of seedlings in rooms with different temperatures. The scientists then recorded the amount of new leaves the plants had per week to see if the temperature of the room had an effect on plant growth.