Even if you used the right specific heat (c) and temperature change (∆T) for ice, for liquid, and for steam, it does not give you the total amount of energy required for this problem. What is still missing, and explain why that requires energy!

Heat of melting s = 333 kJ/kg and heat of vaporisation r= 2160 kJ/kg

Explanation:

percent abundance for cu-63 can be shown as:

63 x + 65 (1-x) = 62.9296

65 - 62.9296 = 2 x

x = 1.035

thus, percent abundance for cu-63 is 1.035

percent abundance for cu-65 can be shown as:

63 x + 65 (1-x) = 64.9278

65 - 64.9278 = 2 x

x = 0.0361

thus, percent abundance for cu-63 is 0.0361

the mass spectrum of cu-63 showing the intense peak as, this isotope is found in nature more abundantly around 92.38 % in comparison to cu-65 which is found 62.58 % naturally