Chemistry 9th Class Important Questions

Chemistry

Important Questions

1. Differentiate between homogeneous and heterogeneous mixture ?
2. Define Free radical ? give example.
3. what is Ion ? Give example.
4. Write two properties of neutron ?
5. Why do the Isotopes of an element have different atomic masses ?
6. What is meant by Dobereiner's triad ?
7. Why Shielding Effect of Electron makes cation formation easy ?
8. Why the Elements are called S and P block element ?
9. Define Bonding electrons ?
10. State Boyle's LAW ?
11. Why are gasses compressible ?
12. Write two properties of ionic compounds ?
13. Define Polar compound ?
14. Define Solvent ?
15. What is Tyndall effect ?
16. Write the names of two things that dissolve in Solvent ?
17. Define Redox reaction ?
18. What is meant by Non Electrolytes ?
19. Define corrosion with example ?
20. how Electroplating of Zinc is carried out ?
21. Write down any two chemical properties of metal ?
22. What is meant by malleability and ductility of metals ?
23. Write down any two uses of magnesium ?
24. Why the second ionization energy of magnesium is higher than the first one ?
25. Define Chemistry ?
26. Difference between atom and ion ?
27. Two properties of neutron ?
28. Two Characteristics of Cathode Rays ?
29. For what purpose U-235 is used ?
30. What is period ? write names of elements of first period ?
31. Define Ionization energy with an example ?
32. Define electronegativity with example ?
33. Differentiate between polar and non polar covalent bond ?
34. What is metallic bond ?
35. effects of inter molecular forces on boiling point ?
36. Water has higher boiling point than alcohol ? Why ?
37. What is compressibility ?
38. What is meant by Standard atmospheric pressure ?
39. Why does evaporation increase when increase in temprature ?
40. What are strong electrolytes ? 
41. Write down two uses of calcium ?
42. Why Alkali metals are more reactive than alkaline earth metals ?
43. Define Nuclear Chemistry ?
44. What is meant by mole ?
45. Define Isotopes ?
46. Define Electronic configuration ?
47. State new-lands and Octaves Law ?
48.