a) State two ways to prevent the rusting of iron . b) Write two physical properties of carbon compounds. c) How was discovery of isotopes proved to be a problem for Mendeleev’s Periodic Table. d) Define Valency. e) Why aluminium oxide is called amphoteric oxide.
Answers
Answer:
a) 1) paint the metal
2) apply oil
3) use an alloy
b) melting point
boiling point
d) a measurement of the power of an atom to combine with others, by the number of hydrogen atoms it can combine with or take the place of
e) Metal oxides which react with both acids and as well as bases to produce salt and water are called amphoteric oxides. Aluminium oxide react both with bases and acids.
Explanation:
a) 1) A good quality paint will slow down rusting by preventing moisture from reaching the metal.
2) A coating of oil will help to prevent rust or slow it down, since it inhibits moisture from reaching the iron in the metal.
3) The use of alloys, like stainless steel, is one of the most common ways to prevent rust, or slow it down.