Chemistry · Electrochemistry

In a free state, an element exists in its elemental form, meaning it consists of individual atoms of that element. In this state, the oxidation number of the element is always zero. The oxidation number, also known as the oxidation state, is a number that represents the hypothetical charge an atom would have if all its bonds were 100% ionic.

The oxidation number of an element in a free state is not negative. Negative oxidation numbers occur when an element gains electrons, indicating that it has undergone reduction and is in a combined state with another element.

The oxidation number of an element in a free state is not positive. Positive oxidation numbers occur when an element loses electrons, indicating that it has undergone oxidation and is in a combined state with another element.

In a free state, an element exists in its elemental form, meaning it consists of individual atoms of that element. In this state, the oxidation number of the element is always zero. The oxidation number, also known as the oxidation state, is a number that represents the hypothetical charge an atom would have if all its bonds were 100% ionic. So, this option is correct.

The oxidation number of an element in a free state is not necessarily +/-1. The oxidation number of an element can vary depending on its chemical environment and the compounds it forms. For example, oxygen in its elemental state has an oxidation number of zero, but in compounds such as water (H2O), it has an oxidation number of -2.