The molecules in liquid water are held together by relatively strong hydrogen bonds and its enthalpy of vaporization, 40.65 kJ/mol is more than five times the energy required to heat the same quantity of water from: 0 °C to 100 °C (cp = 75.3 J K−1 mol−1).
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Answer:
1. Proton = electron if the element is not in an ionic state
proton = atomic number
D = 0.2 g / ml = 0.2 g / cm³
For example, density of steel is 7.85 g / cm³.
Density of pure water is 1.0 g/cm³. An object which has a density < 1.0 g/cm³ will float in water.
Answer: Material that has a density of 0.2 g/ml ( 0.2 g/cm³ ) is good for making couch cushions.
I think the answer would b C