Friday 29th March 2024
REGISTRATION
Online Fashion Store

CBSE Important Questions

CBSE Guess > Papers > Important Questions > Class IX > 2009 > Science > Science By : Mr M. p. Keshri

CBSE CLASS I X

Atoms And Molecules (Solved)

Disable Pop up Blockers to View Solution

Q. 33. Some molecules are given below. Differentiate between them :

(i) chlorine molecule

(ii)0 Argon molecule

(iii) Sulphuric acid molecule

(iv) Hydrogen chloride molecule

(v) Hydrogen molecule

(vi) nitrogen molecule

(vii) Neon molecule.


Answer : Click Here


Q. 34. What is atomicity of an element ? Give examples of mono, dia and triatomic molecules.  


Answer : Click Here


Q. 35.State the basic unit of all material substances.


Answer : Click Here


Q. 36. State molecules containing more than four atoms. What is its name ?


Answer : Click Here


Q. 37. State the ultimate particle on which properties of a material depends.


Answer : Click Here


Q. 38. Choose and explain the correct statement :

(i) Two atoms of hydrogen and one atom of oxygen combine together to form one molecule of water.

(ii) Two molecules of hydrogen and one molecule of oxygen combine to form two molecules of water.


Answer : Click Here


Q. 39. What is difference between 2Cl and Cl2 ?


Answer : Click Here


Q. 40. Name any two molecules having one atom, two atoms and four atoms.


Answer : Click Here


Q.41. Explain the existence of various elements and compounds.


Answer : Click Here


Q. 42. A and B are two different atoms. State whether A and B are metals or non-metals in the following compounds or materials :

(i) A4

(ii) B2

(iii) AB4

(iv) A+2(B-1)2

(v) A2B2

(vi) A+B-

(vii) B

  (viii) B+3(A-1)3.


Answer : Click Here


Q. 43. Differentiate between atom and molecule.


Answer : Click Here


Q. 44. How many kinds of atoms are present in a molecules of

(i) Sulphuric acid and

(ii) Copper carbonate.


Answer : Click Here


Q.45. Separate atoms and molecules from the following stable elements :

Argon, Hydrogen, Helium, Oxygen, Potassium, Neon, Chlorine, Nitrogen, Sodium, Copper.


Answer : Click Here


Q. 46. When one molecule of water is decomposed, how many atoms of hydrogen and oxygen are obtained ?


Answer : Click Here


Q. 47. The atomic masses of hydrogen, carbon, nitrogen, oxygen and sulphur are 1u, 12u, 14u, 16u, 32u respectively. Prove that the atoms of the following compounds combine in simple mass to atomic mass ratio :

CH4, H2O, CO2, NH3, SO2.


Answer : Click Here

Q. 48. Differentiate between an atom of hydrogen and a molecule of hydrogen.


Answer : Click Here


Q. 49. What is the difference between a molecule of oxygen and a molecule of water ?


Answer : Click Here


Q.50. State and explain an ion.


Answer : Click Here


Q. 51. State and explain ionic compound.


Answer : Click Here


Q. 52. Separate the ions in the following compounds :

Sodium fluoride, Potassium bromide, Calcium oxide, Silver sulphide.

Answer : Click Here

Q. 53. What is formula of a molecule ?


Answer : Click Here


Q. 54. State and explain the term ‘valency’. What is use of valency ?


Answer : Click Here


Q. 55.Write the symbols and valency for the common ions of the following :

Potassium, Iodine, Copper, Barium, Fluoride, Cobalt, Sulphide, Aluminium, Zinc, Calcium, Lead, Gold, Sodium, Chloride.


Answer : Click Here


Q.56. Explain why all elements have a charged valency.


Answer : Click Here


Q. 57. Write the name and valency of the following polyatomic ions :

Nitrate, Phosphate, Ammonium, Bicarbonate, Hydroxide, Sulphite, Sulphate, Carbonate.


Answer : Click Here


Q.58. How will you write a molecular formula ?


Answer : Click Here


Q. 59. Write ‘step-wise’ the formula for the following :

(i) Ammonium sulphate

(ii)Potassium carbonate

(iii) Hydrogen sulphide

(iv) Zinc carbonate

(v) Methane

(vi) Cupric chloride.


Answer : Click Here


Q. 60. Calcium pyrophosphate is represented by Ca2P2O7. Represent the ferric pyrophosphate.


Answer : Click Here


Q. 61. Valency of some ions are given below :

Na+1 = 1, Cl-1 = 1,&SO4-2 = 2, Al+3 = 3,CO3-2 = 2
Write the formula of aluminium chloride, aluminium sulphate, aluminium carbonate, sodium chloride, sodium sulphate, sodium carbonate.


Answer : Click Here


Q. 62. Valency or charge of some ions are given below :

Ions  Valency/Charge
Aluminium ion
 +3
Nitride ion 
-3
Magnesium ion
 +2
Sulphate ion
 -2
Potassium ion 
+1
Fluoride ion  -1


Write the chemical formula of the following :

 (i) Aluminium nitride

(ii) Aluminium sulphate

(iii) Aluminium fluoride

(iv) Magnesium nitride

(v) Magnesium sulphate

(vi) Magnesium fluoride

(vii) Potassium nitride

(viii) Potassium sulphate

(ix) Potassium fluoride.


Answer : Click Here


Q. 63. The calcium salt of a hypothetical anion Z has the molecular formula Ca3Z2. Find the valency of Z and write the molecular formula of the aluminium salt of Z.


Answer : Click Here

 


Q. 64. The formula of sulphuric acid is H2SO4 and the formula of a metal chloride is MCl3. What is the formula of metal sulphate ?


Answer : Click Here

 

Paper By Mr. M. P. Keshari [ For Further Enquiry 09434150289]