Can there be oxidation states like +5,+6 and +7?
Apparently you are a bit confused. +7 and -1 are not the same: In terms of oxidation number +x means that the atom of the element has “lost” x electrons (either literally lost them in an ionic bond, or it participates in covalent bonds with more electronegative elements) -x is the opposite that is the atom has “gained” x electrons (either literally gained them in an ionic bond, or it participates in covalent bonds with less electronegative elements) There are elements that can have oxidation number +5, +6,+7 like in the examples mentioned in the other answers (e.g. N has +5 in HNO3, Cr has +6 in K2Cr2O7, Mn has +7 in KMnO4 etc) The sentence you are mentioning “In our text, it has been given that the flourine family has an oxdn state of +7, oxygen – +6 and so on” sounds completely wrong; I am sure you didn’t understand what was written in your textbook, so I can’t really say more than the following. The elements in the same group with fluorine (halogens) have 7 e in their outer shell so
