Answer;
(3) Substance A is an element and substance Z is a compound.
Explanation;
-A compound is a substance formed when two or more chemical elements are chemically bonded together, such as water, carbon dioxide, methane, etc while an element is a pure chemical substance made of same type of atoms, such includes, oxygen, potassium, hydrogen, carbon, etc.
- Compounds can be broken
down or decomposed into simpler substances: elements cannot be broken down chemically into simpler substances .
Answer: Option (a) is the correct answer.
Explanation:
A decomposition reaction is defined as a reaction where a compound dissociates into two or more atoms.
For example, 
Whereas a chemical reaction in which two reactants combine together to result in the formation of a compound is known as a synthesis reaction.
For example,
is a synthesis reaction.
Thus, we can conclude that the statement chemical reaction A, because the reactant is a compound identifies the decomposition reaction and describes a substance is involved.
Answer:
The answer will be C. Variable
Explanation:
The answer will be C because A response is a reactant for the plant and the question is asking about the light. B is incorrect because stimulus is how a plant reacts to nature for example gravitrophism and thingatropism also its asking about the light not the plant. D is incorrect because... come on now does it even make sense XD
Hope this helps
Answer:
1. Jupiter
2. Mercury
3. Venus
4. Venus
5. Jupiter
6. Neptune
7. Mercury
8. Saturn (used to be Jupiter)