"If a metal has more than one mineral form, then it is not necessary that all of them are ores." Justify your statement.

Given below are the pictures of three types of metals and their ores. In each case identify the metal and write its name.

a)

b)

c)

Chromium is mixed with iron to form stainless steel. An iron door knocker gets rusty, but a stainless steel glass never rusts. Thus, if chromium is added to iron, iron's capacity to undergo chemical reaction _____. 

Word list: stronger, weight, decreases.