Question

imagine what would happen if we don't have standard symbols for periodic table?

Answer 1

If the standard symbols for various elements are not used, then there will be confusion in communication between one scientist and industrialist regarding which element they talk about...

In various chemical reactions it is difficult to write the formulas.  Full names have to be written.  The equations will be long.  Formulas for compounds will not be unique.

If there was no periodic table then to understand the properties of various substances, elements, gases, and their reactions among each other will be very difficult.   Learning chemistry of elements and compounds will be very very difficult.  Also prediction of nature of elements and compounds will not be easy at all.

Answer 2

If we don't have standard symbols then everything would be a mess !

All have to remember elements by their names like , CO2 for carbon dioxide , if there were no symbols , there will be confusion & hard to remember all elements & compounds with their names & also if there were names there would be a probability that which elements & compounds have been discovered yet were never being discovered .