What does 43 and 53 grade cement mean?                          252
How does carbon change into diamond?                            252
What is fire made of? What is its atomic structure? What
causes things to burst into flames in the first place
and why can’t all materials be made to produce flame?           253
What makes a cola foam up when you put pretzel in?              254
What causes cooling when glucose is dissolved in water?         255
How does potassium cyanide cause sudden death?                  255
Why can’t ornaments be made with pure gold?
What is the purity (in percentage) of 22 carat
and 18 carat gold?                                              257
Why do salt and sugar readily dissolve in water
and not in oil?                                                 257
What is Pasteurisation? Is it a process of sterilization?       259
Why do plastics become brittle when exposed to the Sun
for a long period?                                              261
Do normal hand soaps actually kill germs? We are always
encouraged to wash our hands after a visit to the toilet,
but does this really make much difference?                      261
Why are soap bubbles and oil layers coloured?                   262
How does soap clean our clothes?                                263
Why is zeolite used in the purification of water?               265
Why does continued use of hard water result in the
formation of a layer in utensils, water filters and boilers?    266
Does cold water extinguish fire faster than hot water?          267
Why does boiled water lose taste?                               267