NCERT/Class 9/Science/Structure of the Atom

Structure of the Atom

Class 9 · Science

44 questions17 easy14 medium13 hard

Sample Questions

Q1.How many electrons can the s orbital hold?

  • A2
  • B6
  • C10
  • D14

Q2.An atom is electrically neutral because:

  • ANumber of protons equals number of electrons
  • BNumber of protons equals number of neutrons
  • CNumber of neutrons equals number of electrons
  • DIt has no charged particles

Q3.Who discovered the electron?

  • AJ.J. Thomson
  • BErnest Rutherford
  • CNiels Bohr
  • DJames Chadwick

Q4.An element with atomic number 26 and mass number 56 has:

  • A26 protons, 26 electrons, and 30 neutrons
  • B26 protons, 30 electrons, and 26 neutrons
  • C30 protons, 26 electrons, and 26 neutrons
  • D26 protons, 26 neutrons, and no electrons

Q5.Heisenberg's uncertainty principle states that:

  • AWe cannot determine both position and momentum precisely simultaneously
  • BElectrons orbit in fixed circles
  • CAll atoms are identical
  • DMass and energy are equivalent

Q6.This is a sample question to preview what you'll get in the full practice test...

  • A. Option one
  • B. Option two
  • C. Option three
  • D. Option four
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Concepts Covered

Atomic NumberAtomic StructureBohr's ModelBohr's TheoryCarbonCathode RaysChargeCharge BalanceChemical PropertiesChlorineElectric ChargeElectron CapacityElectron DensityElectron OrbitsElectron ShellsElectronic ConfigurationElectronsEnergy LevelsEnergy QuantizationEnergy TransitionsHistory of Atomic StructureHistory of Atomic TheoryHistory of ScienceIonization EnergyIonsIronLight FrequencyMagnesiumMass NumberNeonNeutral AtomsNeutronsNoble GasesNuclear ModelNuclear StructureOrbital RadiusOrbitalsOxygenParticle MassPeriodic TablePotassiumProtonsQuantum MechanicsRutherford ScatteringRutherford's ModelShell CapacitySodiumThomsonThomson ModelUncertainty PrincipleValence Electrons

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