Q. Which of the following elements behave as semiconductors in their pure elemental form?

1. Silicon
2. Germanium
3. Gallium

Select the correct option from the codes given below:
Answer: Only 1 & 2
Notes: Silicon and germanium are elemental semiconductors in pure form. Gallium, however, is not a semiconductor as an element; it forms important compound semiconductors such as gallium arsenide. Pure silicon and germanium have suitable electrical properties for their use as intrinsic semiconductors in electronics.