Draw a neat, labelled energy level diagram for H atom showing the transitions. Explain the series of spectral lines for H atom, whose fixed inner orbit numbers are 3 and 4 respectively. The work functions for potassium and caesium are 2.25 eV and 2.14 eV respectively. Is the photoelectric effect possible for either of them if the incident wavelength is 5180 oA ?[Given: Planck's constant = 6.63 × 10^-34 J.s;Velocity of light = 3 × 10^8m/s; 1 eV = 1.6 × 10^-19 J].

Problem 4. Helium is the only known substance that has two different liquid phases called helium-I and helium-II. Use the phase diagram of helium below to answer the following questions.Submit 1 photo that contains the answers to all the parts and label each part (a, b, c, d, e) clearly on your page (5 marks)100Solid10Liquid (HELIUM-I)Pressure (atm)Liquid (HELIUM-I)0.1Gas0.01Temperature (K)a) How many triple points does the diagram have?b) What is the maximum temperature at which helium-II can e

Helium (He) - Physical & Chemical Properties, Uses, Isotopes