Answer: [tex]64.216\times 10^4grams[/tex] of liquid sodium is required.
Explanation: To calculate the mass of liquid sodium, we use the formula:
[tex]q=nc\Delta T\\q=\frac{m}{M}c\Delta T[/tex]
where,
q = heat required, [tex]8.60MJ=8.60\times 10^6J[/tex] Â (Conversion factor: 1MJ = 1000000J)
m = Mass of liquid sodium, [tex]?g[/tex]
M = Molar mass of liquid sodium, [tex]23g/mol[/tex]
c = Specific heat capacity, [tex]30.8J/Kmol[/tex]
[tex]\Delta T[/tex] = change in temperature,  [tex]\Delta T=(510-500)K=10K[/tex]   (Conversion factor: 0°C = 273K)
Putting values in above equation, we get:
[tex]8.60\times 10^6J=\frac{m}{23g/mol}\times 30.8J/Kmol\times 10K[/tex]
[tex]m=64.216\times 10^4grams[/tex]