What picture of the electron is suggested by the quantum-mechanical model of the hydrogen atom? a. a raisin in pudding c. a planetary orbiting body b. a probability cloud d. a light quantum

The atoms in a nickel crystal vibrate as harmonic oscillators with an angular frequency of 2.3 × 1013 rad/s. the mass of a nickel atom is 9.75 × 10-26 kg. what is the difference in energy between adjacent vibrational energy levels of nickel? (h = 6.626 × 10-34 j • s, , 1 ev = 1.60 × 10-19 j)

Acommercial refrigerator with refrigerant-134a as the working fluid is used to keep the refrigerated space at -35°c by rejecting waste heat to cooling water that enters the condenser at 18°c at a rate of 0.25 kg/s and leaves at 26°c. the refrigerant enters the condenser at 1.2 mpa and 50°c. if the compressor consumes 3.3 kw of power, determine (a) the mass flow rate of the refrigerant, (b) the refrigeration load, (c) the cop, and (d) the minimum power input to the compressor for the same refrigeration load.

If a negatively charged particle is placed at rest in an electric potential field that increases in the positive x-direction, what will the particle do? a. accelerate in the positive x-direction b. remain at rest c. accelerate in the negative x-direction