The question poses the differences between a CFL and an LED lamp, focusing on their mode of operation, lifespan, and energy efficiency.

Option 1 indicates that to produce light, a CFL uses mercury vapour and phosphor while an LED lamp uses semiconductor material. This statement is correct. CFL, or Compact Fluorescent Lamps, produce light by passing electricity through a tube containing argon and a small amount of mercury vapor. LEDs, on the other hand, are solid-state devices that produce light by the movement of electrons in a semiconductor material.

Option 2 claims that the average life span of a CFL is much longer than that of an LED lamp. This statement is incorrect. An LED (Light Emitting Diode) actually has a much longer lifespan, typically 25,000 to 50,000 hours, compared to a CFL which typically has a lifespan of 8,000 to 10,000 hours.

Option 3 suggests that a CFL is less energy-efficient compared to an LED lamp, which is correct. LED lamps are known for their higher energy efficiency when compared to CFLs.

So, option 3, which includes statements 1 and 3, is the correct answer.