What are the possible oxidation numbers of an element if its atomic number is 17?

The oxidation number of an element is a number that represents the charge of an atom in a chemical compound. The oxidation number of an element can be determined by following a set of rules. Here are a few rules to help determine the oxidation number of an element: - The oxidation number of a pure element is always 0. - The oxidation number of a monatomic ion is equal to its charge. - In a neutral compound, the sum of the oxidation numbers of all elements is 0. - The oxidation number of oxygen is usually -2, unless it is part of a peroxide or in a superoxide, where it is -1. - The oxidation number of hydrogen is usually +1, except in metal hydrides where it is -1. Using these rules, we can determine the possible oxidation numbers of chlorine (element with atomic number 17). Chlorine can have an oxidation number of -1 or +7. This is because chlorine typically has an oxidation number of -1 in compounds like chloride ions (Cl-) and an oxidation number of +7 in compounds like chlorine gas (Cl2). Therefore, the possible oxidation numbers of chlorine are -1 and +7.