Which coefficient is needed in front of nano3 to balance the equation na2s + zn(no3)2 → zns + _nano3? 1 2 5 7

The  coefficient  that   is needed  in front  of NaNO3  to  balance  the equation  is  2

Explanation

Coefficient    is the  number   in front of a formula  in a balanced chemical equation.

For equation to balance the  number of  atoms in product side  must  be equal  to  number  of  atoms  in reactant  side.

Putting  coefficient 2  in front  of NaNO3  balance  the equation  therefore the balanced equation is as below.

Na₂S  + Zn(NO₃)2   →   ZnS  +  2 NaNo₃.

atomic mass = 39

number of neutrons = 20

number of protons= 19

electronic configuration = 1s2 2s2 2p6 3s2 3p6 4s1

the number of electron in first shell = 2

number of electrons in n=3 shell = 8