Answer:
=7.89013× 10^47 moles of zinc
Explanation:
1 atom contains 6.023×10^23 moles.
1.31×10^24 atoms of zinc contain6.023×10^24×1.31×10^.24
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 : The isoelectronic groups are:



Explanation :
Isoelectronic : It is defined as the compound or molecule having the same number of electrons and the same number of electronic structure.
- The element is helium. The number of electrons are 2.
- The element is beryllium. The number of electrons are 4. The number of electrons in
= 4 - 2 = 2 - The element is lithium. The number of electrons are 3. The number of electrons in
= 3 - 1 = 2 - The element is nitrogen. The number of electrons are 7. The number of electrons in
= 7 + 3 = 10 - The element is neon. The number of electrons are 10.
- The element is sulfur. The number of electrons are 16. The number of electrons in
= 16 + 2 = 18 - The element is magnesium. The number of electrons are 12. The number of electrons in
= 12 - 2 = 10 - The element is titanium. The number of electrons are 22. The number of electrons in
= 22 - 4 = 18 - The element is potassium. The number of electrons are 19. The number of electrons in
= 19 - 1 = 18
The isoelectronic groups are:


