Metaphase
I remember it has meta = middle
Answer:
An experiment that directly test the hypothesis.
Explanation:
Although there is quite a bit missing from Mary's scientific investigation, the thing that sticks out the most is the fact that Mary is missing an experiment. Mary's hypothesis states that people would fall asleep faster if their room color were to be painted blue. To prove that her hypothesis is true, Mary would need to conduct an experiment to see whether or not she was correct.
A compound is always a substance because it's made out of two or more atoms bonded together. Now a substance isn't always a compound because it takes two or more elements to create a compound in a chemical reaction, ans substances can contain only one element. In other words a substance can be constructed of one type of atom. Some substances that aren't compounds are: gold and baking soda.
