What is the total energy required to change 15 g of ice at -20°c to water at 100°c?

To change ice of -20°C to water of 100°C you will need energy of 7524 J.

Explanation:

let q be the heat energy required for that given temperature change, c = 4.18 J/g.°C be the specific heat of water and ΔT be the change in temperature.

then:

the amount of energy required to change ice of temperature -20°C to water at 100°C is:

q = m×c×ΔT

   = (15)×(4.18)×(100-(-20))

   = 7524 J

Therefore, to change ice of -20°C to water of 100°C you will need energy of 7524 J.

beta is electron from nucleus

something from nucleus has changed, but charge must be same for cons of charge