(a)  What property do all elements in the same column of the Periodic Table as boron have in common?
(b)  What property do all elements in the same column of the Periodic Table as fluorine have in common?

Draw the structure for the following compounds.                

       (i)    Ethanoic acid             (ii)   Bromopentane*
       (iii)  Butanone                   (iv)   Hexanal.

*Are structural isomers possible for bromopentane?

Outline a project which aims to find the dominant coat colour in dogs.

How is the sex of the child determined in human beings?

Calculate the number of electrons constituting one coulomb of charge.

A hot plate of an electric oven connected to a 220 V line has two resistance coils A and B, each of 24 Ω resistance, which may be used separately, in series, or in parallel. What are the currents in the three cases?

What is an homologous series? Explain with an example.

A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits – blood group A or O – is dominant? Why or why not?

Why is variation beneficial to the species but not necessarily for the individual?

When a 12 V battery is connected across an unknown resistor, there is a current of 2.5 mA in the circuit. Find the value of the resistance of the resistor.

Give an example of a metal which

  (i) is a liquid at room temperature.
  (ii) can be easily cut with a knife.
  (iii) is the best conductor of heat.
  (iv) is a poor conductor of heat.

If you could use any source of energy for heating your food, which one would you use and why?

How is the sex of the child determined in human beings?

Write the balanced equation for the following chemical reactions.

1. Hydrogen  +  Chlorine  →  Hydrogen chloride
2. Barium chloride  +  Aluminium sulphate  →  Barium sulphate  +  Aluminium chloride
3. Sodium  +  Water  →  Sodium hydroxide  +  Hydrogen

How many structural isomers can you draw for pentane?

Samples of four metals A, B, C and D were taken and added to the following solution one by one. The results obtained have been tabulated as follows.

A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits – blood group A or O – is dominant? Why or why not?

The refractive index of diamond is 2.42. What is the meaning of this statement?

Why is variation beneficial to the species but not necessarily for the individual?

Why are traits acquired during the life-time of an individual not inherited?

Why is the amount of gas collected in one of the test tubes in Activity 1.7 double of the amount collected in the other? Name this gas.