Atoms and molecules

Who postulated the idea of indivisible particles called 'Parmanu'?

• Pakudha Katyayama

• Democritus

• Maharishi Kanad

• Leucippus

What did Democritus call the indivisible particles?

• Parmanu

• Elements

• Atoms

• Molecules

Which law states that mass can neither be created nor destroyed in a chemical reaction?

• Law of Conservation of Mass

• Law of Chemical Combination

• Law of Constant Proportions

• Law of Definite Proportions

Who established the Law of Conservation of Mass?

• Joseph Proust

• Antoine Lavoisier

• Maharishi Kanad

• John Dalton

What is the ratio of hydrogen to oxygen in water by mass?

• 1:2

• 2:1

• 1:8

• 8:1

Which postulate of Dalton's atomic theory states that atoms of different elements have different masses?

• Atoms of a given element are identical

• Atoms cannot be created or destroyed

• Atoms combine in small whole number ratios

• Atoms are indivisible

What is the atomic mass unit (amu) now referred to as?

• Atomic weight (aw)

• Molecular mass (mm)

• Standard mass (sm)

• Unified mass (u)

What is the smallest particle of an element that retains its chemical properties?

• Ion

• Atom

• Compound

• Molecule

What is a molecule?

• A group of two or more atoms bonded together

• A single atom

• A compound

• An ion

Which of the following is a diatomic molecule?

• Oxygen (O2)

• Water (H2O)

• Carbon dioxide (CO2)

• Ammonia (NH3)