Which postulate of Dalton's atomic theory directly explains the law of conservation of mass?

atoms are neither created nor destroyed in a chemical reaction

Which postulate of Dalton's theory explains the law of constant proportions?

atoms combine in a fixed, simple whole-number ratio in a given compound

Which observation would VIOLATE the law of constant proportions if it were ever found true?

pure water samples with different hydrogen-to-oxygen mass ratios

Class 9 · Science · Chemistry

Atoms and Molecules MCQs

Take an interactive Atoms and Molecules quiz for Class 9 Science - tap an answer for instant feedback and a step-by-step solution. These are a few sample questions; practice the full Atoms and Molecules set free on the RankByte app.

Topics covered

Laws of Chemical Combination (Conservation of Mass, Constant Proportions)Atomic Mass and Molecular MassMole Concept and Avogadro's NumberWriting Chemical FormulaeValency and IonsLaws of Chemical CombinationChemical FormulaeMolecular and Formula MassMole ConceptLaws of chem combination, mole concept, formulae

Practice Atoms and Molecules by topic

Focused MCQ quizzes for each topic.

Atomic Mass and Molecular Mass Chemical Formulae Laws of Chemical Combination Laws of Chemical Combination (Conservation of Mass, Constant Proportions)Laws of chem combination, mole concept, formulae Mole Concept Mole Concept and Avogadro's Number Molecular and Formula Mass Valency and Ions Writing Chemical Formulae

Atoms and MoleculesQuiz - Solve & Score

A few sample questions with instant answers and solutions - the full set is in the app.

Q1. Which postulate of Dalton's atomic theory directly explains the law of conservation of mass?
- A.atoms are neither created nor destroyed in a chemical reaction
- B.atoms of different elements have different masses
- C.atoms combine in small whole-number ratios
- D.atoms are divisible into electrons
Answer: A. atoms are neither created nor destroyed in a chemical reaction
Q2. Which postulate of Dalton's theory explains the law of constant proportions?
- A.atoms combine in a fixed, simple whole-number ratio in a given compound
- B.atoms are neither created nor destroyed
- C.atoms are indivisible
- D.all matter is made of atoms
Answer: A. atoms combine in a fixed, simple whole-number ratio in a given compound
Q3. Which observation would VIOLATE the law of constant proportions if it were ever found true?
- A.pure water samples with different hydrogen-to-oxygen mass ratios
- B.all pure water having the same 1:8 H:O ratio
- C.mass being conserved in a reaction
- D.excess reactant remaining unreacted
Answer: A. pure water samples with different hydrogen-to-oxygen mass ratios