Astudent makes several observations about a piece of iron. which observation describes a chemical property of the iron?

Here we have to identify a piece of iron by its chemical property.

There are several chemical properties of iron for its identification but the simplest way to identify one of the renowned chemical property of iron is the formation of rust on iron in presence of water.

The iron in presence of water forms different types of iron oxides like hydrated Iron (III) oxide [Fe₂O₃.nH₂O], Iron (III) oxide-hydroxide [FeO(OH). Fe(OH)₃].

The rust is brown in color and forms only by keeping the iron piece in atmosphere. Although the humidity has an effect on the formation. The more humid the atmosphere there will be more chance to form rust on iron rod.

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.

am i too late?

explanation: