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1250 Important Chemistry MCQ Question and Answer PDF

4000 Important General Science MCQ Question & Answer in PDF Download

1.The electronic configuration of an atom having atomic number ?20? is

  • A2, 8, 10
  • B2, 6, 8, 4
  • C2, 8, 8, 2
  • D2, 10, 8
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Correct Answer : (C)

2, 8, 8, 2
Explanation:

2.A mixture of water and alcohol can be separated by

  • AFiltration
  • BEvaporation
  • CDecantation
  • DDistillation
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Correct Answer : (D)

Distillation
Explanation:

3.The orientation of an atomic orbital is governed by

  • APrincipal quantum number
  • BMagnetic quantum number
  • CSpin quantum number
  • DAzimuthal quantum number
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Correct Answer : (B)

Magnetic quantum number
Explanation:

4.Rutherford's scattering experiment proved the presence of

  • AAtoms in all matter
  • BElectrons in atoms
  • CNeutrons in atoms
  • DNucleus in atoms
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Correct Answer : (D)

Nucleus in atoms
Explanation:

5.When a metal is heated in a flame, the electrons absorb energy and jump to higher energy state. On coming back to the lower energy state, they emit light which we can observe in

  • ARaman spectra 
  • BAbsorption spectra
  • CEmission spectra
  • DFluorescence
Answer / Hint Save Question
Correct Answer : (C)

Emission spectra
Explanation:

6.Which one of the following has greatest mass?

  • AElectron
  • BProton
  • CNeutron
  • DHydrogen nucleus
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Correct Answer : (C)

Neutron
Explanation:

7.A colloidal system in which a liquid is dispersed in a liquid is called

  • AGel
  • BEmulsion
  • CSol
  • DPrecipitate
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Correct Answer : (B)

Emulsion
Explanation:

8.Heavy water is so called because it contains

  • AHeavy isotope of hydrogen
  • BHeavy isotope of oxygen
  • CMole number of hydrogen atoms
  • DMole number of oxygen atoms
Answer / Hint Save Question Comment On Question
Correct Answer : (A)

Heavy isotope of hydrogen
Explanation:

9.The nuclear particle having no mass and no charge, but only spin is

  • AProton
  • BNeutrino
  • CMeson
  • DElectron
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Correct Answer : (B)

Neutrino
Explanation:

10.In a period from Li to F, ionisation potential

  • ACannot be predicted
  • BIncreases
  • CDecreases
  • DRemains same
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Correct Answer : (A)

Cannot be predicted
Explanation:

11.Ionisation energy of nitrogen is greater than that of oxygen because nitrogen has

  • AHigh bond dissociation energy
  • BSmaller atomic radius
  • CStable half filled 2p sub level
  • DHigh nuclear charge
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Correct Answer : (C)

Stable half filled 2p sub level
Explanation:

12.Atomic theory of matter was given by

  • AAvogadro
  • BDalton
  • CNewton
  • DPascal
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Correct Answer : (B)

Dalton
Explanation:

13.Which among the following is a covalent compound?

  • ACalcium chloride
  • BMagnesium fluoride
  • CSodium chloride
  • DCarbon tetrachloride
Answer / Hint Save Question
Correct Answer : (D)

Carbon tetrachloride
Explanation:

14.Which of the following is the maximum number of electrons that can be present in M-shell?

  • A2
  • B8
  • C18
  • D32
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Correct Answer : (C)

18
Explanation:

15.Atoms of different elements have

  • ASame atomic number and same electronic configuration
  • BDifferent atomic number and same electronic configuration
  • CDifferent atomic number and different number of valence electrons
  • DSame number of electrons and neutrons
Answer / Hint Save Question
Correct Answer : (C)

Different atomic number and different number of valence electrons
Explanation:

16.Nucleons are regarded as composites sub-particles known as

  • AMesons
  • BQuarks
  • CLeptons
  • DPhotons
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Correct Answer : (B)

Quarks
Explanation:

17.In the periodic table of elements, on moving from left to right across a period, the atomic radius

  • ADecreases
  • BIncreases
  • CRemains unchanged
  • DDoes not follow a definite pattern
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Correct Answer : (A)

Decreases
Explanation:

18.Number of neutrons in an atom of hydrogen is

  • A1
  • B0
  • C2
  • D3
Answer / Hint Save Question
Correct Answer : (B)

0
Explanation:

19.Who developed the model of atomic structure?

  • ABohr and Rutherford
  • BVolta
  • CAlfred Nobel
  • Dfaraday
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Correct Answer : (A)

Bohr and Rutherford
Explanation:

20.When a bond is formed is formed between two atoms, the energy of the system will

  • AIncrease
  • BDecrease
  • CRemain the same
  • DMay increase or decrease
Answer / Hint Save Question Comment On Question
Correct Answer : (C)

Remain the same
Explanation:
4000 Important General Science MCQ Question & Answer in PDF Download

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