18. the blank should be "
"
19. the question seems to be answered.
20. 
Answer:
1 mol
Explanation:
The mass of CoCl2 is 129.83. 130 divided by the mass is 1. This is to convert the mass given to mols that exist in the sample.
Both in the phase of a liquid & has similar qualities like both molecules.
Answer:
COMMENSALISM
Explanation:
Commensalism refers to the relationship that exists between two different organism that belong to different species. In this relationship neither of the organisms are harmed while either of them is benefitted. The web made by the spider between the horns of the deer increases the probability of the spider to catch its prey. The random movement of the deer helps the spider and at the same time it do not harm the deer.
I believe the answer is B, or option 2. It makes the most sense, and is a fact.
