In this reaction what is the correct coefficient for sodium chloride? pb(no3)2 ? nacl → pbcl2 ? nano3

2

Explanation:

The unbalanced reaction is shown below as:-

On the left hand side,  

There is 1 lead atom and 2 nitrogen atoms and 6 oxygen atoms  and 1 sodium atom and 1 chlorine atom

On the right hand side,  

There is 1 lead atom and 2 chlorine atoms and 3 oxygen atoms  and 1 sodium atom

Thus,  

Right side, must be multiplied by 2 so to balance nitrogen and oxygen.

Left side, is multiplied by 2 so to balance the whole reaction.

Thus, the balanced reaction is:-

Coefficient of the sodium chloride in the balanced equation - 2

i believe it is-

d.) gravity pulled particles of dust and gas together to form planets.

i have no clue hope you find the answer