9. What is useful in constructing scientific questions, methods, and explanations? A. formaldehyde
B. a large research team
C. a very limited amount of time
D. creativity

C

creativity

Explanation:

C. Because the results of some experiments might not be explained by any

known theories.

answer: e.   sour taste

explanation: acids are those substances which dissociates in water to give ions. as they dissociate to give ions, they act as electrolytes and thus are electrically conductive. acids are sour in taste. example: hcl

bases are those substances which dissociates in water to give ions or accepts ions. as they dissociate to give ions, they act as electrolytes and thus are electrically conductive. bases are bitter in taste. bases are slippery in nature.

elements make up everything, and they combine to make compounds.

the answer is c