Saturday, February 23, 2013

CBSE Class 9 - Science - CH3 - Atoms and Molecules (MCQs)

Atoms and Molecules 
CBSE Class 9 - Science - CH3 - Atoms and Molecules (MCQs)


Q1: Name the Indian Philospher who "the smallest indivisible particles of matter" as Parmanu

(a) Pakudha Katyayama
(b) Maharishi Kanad
(c) Aryabhatt
(d) Democritus

Q2: Who laid the foundation of laws of Chemical Combination:

(a) Democritus
(b) Lavoisier
(c) Dalton
(d) Proust

Q3: Law of Definite Proportions was proposed by:

(a) Joseph Proust
(b) John Dalton
(c) A Lavosier
(d) Wilhelm Ostwald

Q4: Who introduced the term 'mole' in chemistry?

(a) John Dalton
(b) Amedeo Avagadro
(c) A Lavosier
(d) Wilhelm Ostwald

Q5: The number value 6.022 × 1023 is also called

(a) Dalton Number
(b) Avagadro's number
(c) Atomic Number
(d) Mass Number

Q6: The number of moles for 52g of He is:
(Atomic Mass of He: 4u)

(a) 6.022 × 1023
(b) 13
(c) 52
(d) 1

Q7: 1 u or 1 amu means

(a) 1/12th mass of C-12 atoms
(b) Mass of C-12 atom
(c) Mass of O-16 atom
(d) Mass of Hydrogen molecule

Q8: Formula for Magnesium Chloride is:

(a) MgCl
(b) Mg2Cl
(c) MgCl2
(d) MgCl4

Q9: Formula for Aluminium Oxide is:

(a) AlO
(b) AlO2
(c) Al3O2
(d) Al2O3

Q10: The percentage of Hydrogen in H2O molecule is

(a) 5.55
(b) 11.11
(c) 44.45
(d) 88.89

Q11: A sample of ammonia molecule irrespective of source, contains 82.35% of Nitrogen and
17.65% of Hydrogen by mass. This data supports:

(a) Law of Conservation of Mass
(b) Law of Definite Proportions
(c) Las of Multiple Proportions
(d) Avagadro's Law

Q12: Which of the following is not correctly matched?

(a) Calcium - Ca
(b) Silver - Ag
(c) Gold - Au
(d) Copper - Co

Q13: Which of the following will have maximum mass?

(a) 0.1 mole of NH3
(b) 1022 atoms of Carbon
(c) 1022 molecules of CO2
(d) 1 gm of Fe

Q14: An element X is tetravalent and another element Y is divalent.
The compound formed by these two elements will be:

(a) XY
(b) XY2
(c) X2Y
(d) XY4


  1. This comment has been removed by the author.

  2. Replies
    1. Not better only good question

    2. Not better only good question

  3. Please provide few more questions for ssc cgl exam

  4. The answer for Q.1 is wrong
    Correct answer is (b) Maharishi Kanad

    1. The answer is that only are u not able to see

    2. The answer is that only are u not able to see

    3. Are bhai vahi to diya hai answer mai

  5. Replies
    1. ya calculatory questions are needed more for practise

  6. Good mcq questions....but give other numerical questions..

  7. super...........very useful question.......thanks for help

  8. Replies
    1. It is correct. X is tetravalent (valency = 4) and Y's valency = 2. It becomes X2Y4 i.e. XY2 (option b)