Question

1) How can you protect the following from rusting? [2 MARKS]
(a) Iron mug
(b) An iron spoon
(c) Bicycle handle
(d) Bicycle chain

2) Write a short note on the electronic nature of non-metals? [3 MARKS]

Answer 1

1) Each Part: 0.5 Marks
2) 3 Marks

1) Protection from rusting:
(a) Iron mug: By enameling
(b) An iron spoon: By converting iron into stainless steel
(c) Bicycle handle: By coating with Cr or Ni electrolytically
(d) Bicycle chain: By applying grease

2) i) Non-metals form ions by gaining electrons. For example, oxygen is a non-metal which forms $O^{2-}$ ions by gaining two electrons. Similarly, nitrogen forms $N^{3-}$ ions by gaining three electrons. Thus, non-metals are also known as electronegative elements.
ii) The atoms of non-metals usually have 4 to 8 electrons in their outer most shell. For example, Carbon (Z= 6), Nitrogen (Z= 7), Oxygen (Z= 8), Fluorine (Z= 9) and Neon (Z= 10), have 4, 5, 6, 7 and 8 electrons respectively in their outermost shell.
iii) However, there are two exceptions namely hydrogen and helium which have one and two electrons in their valence shell or outer most shell, but they are non-metals.