They are saying that every theory can eventually be changed a bit due to further research. It does not mean the theory is bad, just that it can become better.
Givens
m = 2.26 g
c = 4.19 J/(g * oC)
Δt = 23.5oC - 0 = 23.5oC
hf = heat of fusion for ice = 334 J/g
Equation
H = m*c*Δt + hf * m
H = m*(c*Δt + hf)
Solution
H = 2.26 * (4.19 * 23.5 + 334)
H = 2.26 * (432.5)
H = 977.4 J
Yes it is due to refraction of light in water
Answer:
Carbon has an atomic number of 6. That means a carbon atom has 6 protons, 6 neutrons, and 6 electrons.