Answer: c. elements in the same row of the periodic table
Explanation: It kind of represents a graph of the periodic table
CFCs and their associated compounds were developed in the early 1900s as a non-toxic, non-flammable solution to other more dangerous products such as ammonia.
Answer:
cream - contains a higher proportion of oil than water
ointment - dr4g mixed in approximately equal proportions of oil and water
i don't know about the other two sorry
The answer is C because the weight is going down so they form a gas.