Available Answers

1. 1.

   State the meaning of the term 

   1. atom
   2. molecule
   3. radical

   with a suitable example.

2. 2.

   Draw the basic structure of an atom representing its-

   1. Subatomic particles
   2. Nucleus
   3. Orbits or shells
3. 3.

   In the Modern Periodic Table atoms of all elements are arranged according to their increasing order of - atomic numbers. An atom of nitrogen has seven protons & seven electrons. State what would be its atomic number.

4. 4.

   State the main points of contradiction of Dalton's atomic theory by the Modern Atomic Theory.

5. 5.

   'Atoms of the same element or different elements combine to form a molecule'.

   Give two examples each of-

   1. atoms of the same element
   2. atoms of different elements combining to form a molecule.
6. 6.

   Explain the term - 'atomicity'. Give a reason why -

   1. Helium is considered monoatomic, but hydrogen a diatomic molecule.
   2. Ozone is considered triatomic but phosphorus a tetratomic molecule.