Respuesta :
Answer:
A
Explanation:
In other options, they form positive ion as they have extra electrons in their valence shell
But in group 17, all the elements have 7 electrons in their valence shell,inorder to attain octet they require one more electron
Hence,they form negative ion by gaining electron
Answer:
A
Explanation:
An element from group 17 wants to gain an electron to from a negative ion. A metal forms only positive ions, an element from group 1 will lose to form a positive ion and elements with eight valence electrons are normally very stable, meaning they don't need to lose or gain.