Answer:
In a chemical reaction, there is a change in the composition of the substances in question; in a physical change there is a difference in the appearance, smell, or simple display of a sample of matter without a change in composition. Although we call them physical "reactions," no reaction is actually occurring.
An anion is a negatively charged ion. An element can become an anion if it takes an extra electron such that it has one more electron than protons.
Atoms would preferentially taken an extra electron so that it can have a full octet and be more stable.

are some of the few elements that would have a -1 charge.
Answer: A. The compound CuCl is 500 times less soluble in sea water than it is in pure water.
pure water.
Explanation:
Any change in the equilibrium is studied on the basis of Le-Chatelier's principle.
This principle states that if there is any change in a equilibrium reaction, the equilibrium will shift in a direction so as to minimize the effect.
Thus when a common ion is introduced to an equilibrium reaction, the equilibrium will shift in a direction where the concentration of common ion is decreasing.


When common ion such as
from NaCl in sea water is introduced to an equilibrium reaction, the equilibrium will shift in a direction where the concentration of common ion is decreasing i.e. in the left side and thus solubility of CuCl further decreases.