Mukesh is student of class X. He lives in a big house. There is a big iron gate in the boundary wall of his house which was installed about one year back. For the last few days, Mukesh has been observing that red -brown pathces have appeared at some of the places on the iron gate. When Mukesh brought this development to the notice of his family, his sister, who is a student of class VI, said that the iron gate should be cleaned properly with sand paper to remove the red -brown patches and then smeared with oil on grease to protect it fro further damage. Mukesh did not agree with her and suggested a different teatment for the iron gate. Mukesh's father also agreed with his plan of action.
(a) What are the red brown patches on the surface is iron gategt Name the process which leads to the formation of these patches.
(b) What conditions are necessary for the formation of red-brown patches on the iron gate?
(c) What har canbe done if this iron gate having red-brown patches is allowed to remain as such for a long time (without any treatment)?
(d) Explain why this iron gate cannot be smeared with oil or grease to protet it form further damage?
(e) What treatment do you think was suggested by Mukesh to protect the iron gate from further damage?
How does this treatment work to protect the iron gate?
(f) What values are displayed by Mukesh in this episode?

Explanation

(a) The red brown patches on the surface of iron gate are of rust. The red brown patches are formed due to the rusting of iron (of the iron gate).
(b) The conditions necessary for the rusting of iron to take place are (i) presence of air and (ii) presence of water (or moisture). In this case of rusting of iron gate damp air (or moist air) present around the iron gate provides both the conditions air and water (or moisture) required for the rusting of iron.
(c) If this rusted iron gate is allowed to remain in this way, then the soft and porous rust will keep on falling from the surface of iron gate and then the fresh iron below will start rusting. The rusting of iron is a continuous process which will ultimately eat up the whole iron gate and make it useless.
(d) The iron gate cannot be smeared with oil or grease hecause this oil and grease will spoil the hands and clothes of a person when the gate is opened or closed. Moreover, oil and grease can be washid away by rains.
(e) Mukesh suggested the painting or iron gate. When a coat of paint is applied to the surface of this iron gate, then air and moisture (present in moist air) cannot come in contact with the iron of iron gate and hence no rusting will take place.
(f) The values displayed by Mukesh in this episode are (i) Keen Observation (ii) Awareness of rusting and conditions necesary for rusting (iii) Understand of correct method of prevention of rusting to be applied, and (iv) Desire to protect the iron gate of his house from further damage.