Atoms and Molecules

Class 9 · Science

54 questions18 easy24 medium12 hard

Sample Questions

Q1.Which particle has negligible mass?

AElectron
BProton
CNeutron
DAlpha particle

Q2.What is a compound?

AA substance made of two or more elements in fixed proportions
BA pure element
CA mixture of atoms
DA single type of atom

Q3.How many molecules are present in 2 moles of CO2?

A1.204 × 10^24
B6.022 × 10^23
C3.011 × 10^23
D2.411 × 10^24

Q4.What is polyatomic ion?

AA charged group of atoms bonded together
BA single charged atom
CA neutral group of atoms
DAn elemental ion

Q5.What is the mass number of an atom?

ANumber of protons + number of neutrons
BNumber of protons + number of electrons
CNumber of neutrons only
DAtomic mass in grams

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

AmmoniaAnionsAtomic MassAtomic Mass UnitAtomic NumberAtomic StructureAtomsAvogadro's NumberBenzeneCalcium OxideCalculationsCarbon DioxideCationsChemical BondingChemical FormulasChlorineCompoundsCounting AtomsDalton's TheoryDiatomic MoleculesElectron ChargeElectron ShellsElectron TransferElectronic ConfigurationElectronsElementsEmpirical FormulaFundamental ConstantsGas LawsHistory of ChemistryIonic BondingIonic CompoundsIonsIsobarsIsotopesLaws of Chemical CombinationMassMass ConservationMass NumberMass PercentageMeasurementMethaneMolar MassMolar VolumeMolecular FormulaMolecular FormulasMoleculesMolesNitrogen CompoundsOxygenOxygen GasPercent CompositionPeriodic TablePolyatomic IonsRadicalsRadiocarbon DatingRatiosSTPShell CapacitySignificant FiguresSodiumSodium ChlorideSubatomic ParticlesSulfate IonValence ElectronsValencyWater

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