Which element forms the maximum number of compounds in chemistry?

Saline hydrides are known to react with water violently producing fire. Can $CO_2$,a well-known fire extinguisher,be used in this case? Explain.

The natural relative abundance of isotopes of hydrogen is:

Which of the following explanations is best for not placing hydrogen in either the group of alkali metals or halogens?

In the synthesis of which compound is water gas used?

Which of the following is expected to be high for a proton $(H^+)$?