The colour discharge tubes for advertisements mainly contain
A) Argon
B) Neon
C) Helium
D) Xenon

Hint: We know that argon, helium, xenon, etc. all are inert gases placed in the last group of the periodic table. They have many applications in our life.

Complete Step by Step Solution:
Let’s discuss the element neon in detail. It is an inert gas whose atomic number is 10. It has an electronic configuration of 2,8. So, its valence shell is fully filled. Therefore, it has a non-reactive nature.

Now, we will discuss some uses of neon.
1) It is used to make advertising signs.
2) Its use to make TV tubes is also significant.
3) It is also useful in making gas lasers.
4) The liquid form of neon is very useful as a refrigerant. Its refrigerant capacity is forty times of liquid helium. Also, neon is cheaper than helium as well
5) It is useful in making epic lamps.
Therefore, the noble gas that is used in the colour discharge tube for the purpose of advertisement is neon.
Hence, option B is right.

Note: There are many uses of argon, such as the mixture of argon with nitrogen when filled in electric bulbs, its filament’s life will increase. It is also used to create an inert atmosphere in welding. When it is mixed with neon, lights of various colours are obtained. The helium gas is used in inflating balloons. The use of xenon as a flashlight in photography, various lasers, and bactericidal lamps are significant.