Which group of 1A elements are less dense than pure water at 4°C

Specific heat capacity is the required amount of heat per unit of mass in order to raise teh temperature by one degree Celsius. It can be calculated from this equation: H = mCΔT where the H is heat required, m is mass of the substance, ΔT is the change in temperature, and C is the specific heat capacity.

H = mCΔT
2501.0 = 0.158 (C) (61.0 - 32.0)

C = 545.8 J/kg·°C