Position of Hydrogen in the Periodic Table

According to group I

Similarities

• Both hydrogen and alkali metals have one electron in their outermost shell.
• Both form positive ions as they lose electron.
• Both have strong tendency to combine with more electronegative atom such as flourine
• Both form ionic compounds which dissociate in water.

Differences

• In a true sense, Hydrogen doesn't lose electron as easily as alkali metals do because it is non-metal basically
• It is found in molecular state in the atmosphere but alkali metals don't exist in such a form.

According to group VII A

Similarities

• They have similarity in their physical state as both exist in gaseous form
• Both are diatomic in nature as H2 and F2
• Both need one electron to fill their outermost electron
• They form stable ionic compounds with alkali metals

Differences

• After removing one electron Hydrogen forms positive specie but halogens don't do that
• Hydrogen made stable compounds with oxygen while halogens have no tendency to do that.

According to group IV A

Similarities

• Both sides have half filled orbitals
• Form covalent bonds with other atoms
• Both have reducing abilities

https://chemiday.com/en/reaction/3-1-0-625
Differences

• Hydrogen in unable to form long chains as carbon and silicon can
• Hydrogen forms only single bond while carbon can form four bonds because of availability of electrons

Hydrogen is very specific in nature and its properties doesn't match with any group but due to some similar features with group IA and its monovalent nature it has been placed on the top of the group IA.