SHORTANSWERQUESTIONSu15. Why is zinc better than tim in profecting iron from fusting16. Rusting of iron pipe can be17. Iron pipes are generally coated with zinc. Explain.18, Why copper turn green when kept open in air for long time?19. How protons are made available initially at cathodic'site on iron during rusting?

SHORTANSWERQUESTIONSu15. Why is zinc better than tim in profecting iro

1.	SHORTANSWERQUESTIONSu15. Why is zinc better than tim in profecting iron from fusting16. Rusting of iron pipe can be17. Iron pipes are generally coated with zinc. Explain.18, Why copper turn green when kept open in air for long time?19. How protons are made available initially at cathodic'site on iron during rusting?
Answer» Galvanising is a method ofrustprevention. Theiron orsteel object is coated in a thin layer ofzinc. This stops oxygen and water reaching the metal underneath - but thezincalso acts as a sacrificial metal.Zinc ismore reactivethan iron, so it oxidises in preference to theironobject.