It is 2.1 x 10^3 because your base number needs to be in between 1 and 10, and the number you are converting is non-decimal, so the exponent is positive. It is 10^3 because you are moving the decimal 3 places to the right
Answer : The maximum amount of nickel(II) cyanide is 
Explanation :
The solubility equilibrium reaction will be:

Initial conc. 0.220 0
At eqm. (0.220+s) 2s
The expression for solubility constant for this reaction will be,
![K_{sp}=[Ni^{2+}][CN^-]^2](https://tex.z-dn.net/?f=K_%7Bsp%7D%3D%5BNi%5E%7B2%2B%7D%5D%5BCN%5E-%5D%5E2)
Now put all the given values in this expression, we get:


Therefore, the maximum amount of nickel(II) cyanide is 
Answer=1
Potassium Sulfide= K2S (two metals, one non metal)
Sodium Oxide=Na2O (two metals. one nonmetal)
Sodium Chloride=NaCl (one metal, one nonmetal)
Magnesium Oxide=MgO (one metal, one nonmetal)
Magnesium Chloride=MgCl2 (one metal, two nonmetals)
Answer is: the identity of the isotope is silver (Ag-107).
p⁺(isotope) = 47; number of protons in isotope.
Z = p⁺; atomic number.
Atomic number is the number of protons, which is characteristic of a chemical element, silver is an element with atomic number 47.
n°(isotope) = 60; number of neutrons in isotope.
A = p⁺ + n°; mass number is the total number of protons and neutrons in a nucleus.
A = 47 + 60.
A = 107.