Not sure about #6 , but i got all the other answers
Answer:
2CaO + 2CO2 → 2CaCO2 + O2 is right
Entropy is a measure of chaos or disorder in a system. For the first one, the system with the highest entropy is a cup of water at 0 degress centigrade. For the second question, the system with the lowest entropy is sugar crystals in 95 degrees centigrade cup of coffee.
During absorption, frequency of the incoming light wave is either near or at the energy level of the electrons in the matter of the material. The electrons will absorb the energy of the light wave and change their energy state.
Hope that helps! :)
The speed of sound is given by the formula
Speed of sound = square root (Young's Modulus/density)
Young's modulus for gold = 78 GPa which is 7.8 * 10^10 Pa
Speed of sound = (7.8 * 10^10 / 19.3 ) = sqrt (4.04 * 10^9 )
Speed of sound = 6.36 * 10^4 m/s <<<=== answer.
