Crylo i think is the correct answer
Answer:
Six
The coordination number of sodium is 6. Likewise, six sodium ions immediately surround each chloride ions, making the coordination number of chloride also equal to 6. Because the formula unit of sodium chloride displays a 1:1 ratio between the ions, the coordination numbers must be the same.
A is the answer, and put the choices
the number of Valence electrons remains the same
A. : In this reaction one of the product, FeS is insoluble. Therefore, this is a precipitation reaction.
B. : In this reaction, the product is a solid(insoluble). So, this is a precipitation reaction too.
C.: In this reaction, both the products are soluble. So this is not a precipitation reaction.
D.: In this reaction, both the products are soluble. So this is not a precipitation reaction.
E. : In this reaction, the product AgCl is a precipitate. So, it is a precipitation reaction.