Why does iron have no oxidation state corresponds to loss of all it's valence electrons?

When an element loses an electron, its oxidation number increases.

Explanation:

The oxidation number of an element indicates the hypothetical charge of an atom in a compound. It is hypothetical because, in the context of a compound, the elements may not necessarily be ionic. When the number of electrons associated with an atom changes, its oxidation number also changes. When an element loses an electron, its oxidation number increases.

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e

1. they vary with a higher number because boiling is way hotter than melting