Question

Why the position of hydrogen called controversial?

Answer 1

Answer:

because in its valence shell there is 1 electron which is similar to 1st group

but it shows -1 oxidation state also which is similar to 17th group

so it's position is controversial

Answer 2

The position of hydrogen has always been a controversial as some of it's properties resembled

alkali metals while some resembled halogens

• it had Valence shell electronic configuration just like alkali metals
• it required 1 electron to attain noble gas configuration just like halogens
• It can form protons like alkali metals
• it can form diatomic molecules like halogens
• it had high ionisation energy like halogens

HOPE IT IS HELPFUL