Structure of Atom-Sample Questions

Class IX Science
Sample Paper for Structure of the Atom
1.   Give difference between isotopes and isobars.
2.   Number of protons and electrons are same in an atom. Then why is it wrong to say that atomic number of an atom is equal to its number of electrons.
3.   An atom is electrically neutral, on loss or gain of electrons why does it become charged?
4.   What is valency? Explain different types of valencies.
5.   According to you, among the structure of atom studies which model is correct and why?
6.   Give an activity to understand the implications of Rutherford’s α scattering experiment by a gold foil.
7.   Explain Rutherford’s α-particle scattering experiment and give its observation and conclussion drawn.
8.   Establish the relationship between atomci number, mass number, isotopes, isobars and valency of an atoms.