#### Condensed State Physics

Partial Melt. If 2×105 J of energy in terms of heat is transferred to 3 kg of ice at 0 °C, how much ice melted in kg?

Partial Melt. If 2x105 J of energy in terms of heat is transferred to 3 kg of ice at 0 °C, how much ice melted in kg?

1. What is the total heat Q requires to melt a 2 kg ice at -5 °C to water at +10 °C ? Hint there is a phase change in the system. There are 3 separate Qs.

7. An object is hung from scale and the reading is recorded to be 20 N. Then the object is completely immersed in water.What is the new scale reading if the object has a volume of 12.5x105 m². The density of water is 1000kg/m³

One considers the coupling of the orbital angular momenta of two p electrons. a) From the tables of the Clebsh-Gordan coefficients, give the explicit form of the following states: |L M> = |2 2>, 12 1>, |2 0>, |1 1>, |1 -1> et 0 0>. b) What can you say about the symmetry properties of the obtained states with respect to the exchange of the two electrons?

Two moles of ideal mono atomic gas releases 6 000 J of heat when it is compressed by an external force. A 2 000J ofwork done on the gas during compression. 3. What is the change in the internal energy of the gas? 4. What is the change in the temp of the gas in Kelvin?

a) What are the values of the quantum numbers S, L and J in the ground state of nitrogen? b) What are the angles between the total angular momentum , and the quantification axis z?

5. An Aluminum rod is 20 cm long at 20 °C and has a mass of 350 g. If 10,000 J of thermal energy is added to the rod by heat, what is the change in the length of the rod in cm?

2.One way to heat a gas is to compress it. When a certain gas under pressure of 2,000,000 Pa at 298.15 Kelvin is allowed to be compressed to 1/4 of its original volume, its final pressure is 3 times the initial pressure. What is its final temp?Hint use ideal gas law.

6. A hot-air balloon has a volume of 2200 m². The basket, passengers and the balloon fabric (the envelope) weight 5,800 N,excluding the weight of heated gas in the envelope. If the balloon is floating in the air without accelerating upward or downward when the outside air density is 1.23 kg/m³, what is the average density of the heated gases in the envelope?

Show from the Tables of the Clebsh-Gordan coefficients that the singulet and triplet states resulting from the coupling of the intrinsic spins of the two electrons of the He atom are indeed those given by the relations (II.23) and(11.24.11.25.11.26.) of the lecture notes.