Atoms and Molecules - Set 1 | Class 9 Science MCQ Quiz

1. According to the Law of Conservation of Mass, what happens to mass in a chemical reaction?

A) It is created but not destroyed. B) It is destroyed but not created. C) It can neither be created nor destroyed. D) It can be both created and destroyed.

2. In a water molecule, what is the ratio by mass of hydrogen to oxygen, irrespective of its source?

A) 1:16 B) 1:8 C) 2:1 D) 8:1

3. Which of the following is a postulate of Dalton's atomic theory?

A) Atoms are divisible particles. B) Atoms can be created or destroyed in a chemical reaction. C) Atoms of a given element are identical in mass and chemical properties. D) Atoms combine in variable ratios to form compounds.

4. Which ancient Greek philosopher called the indivisible particles of matter 'atoms'?

A) Maharishi Kanad B) Pakudha Katyayama C) Democritus D) Antoine L. Lavoisier

5. In 1961, which isotope was chosen as the standard reference for measuring atomic masses universally?

A) Oxygen-16 B) Hydrogen-1 C) Carbon-12 D) Sulphur-32

6. What is the atomicity of a molecule of oxygen (O₂)?

A) Monoatomic B) Diatomic C) Tetra-atomic D) Poly-atomic

7. A negatively charged ion is called a/an:

A) Cation B) Anion C) Polyatomic ion D) Molecule

8. Which international scientific organisation approves names of elements, symbols, and units?

A) NASA B) WHO C) IUPAC D) UNESCO

9. Using the atomic masses provided in the PDF (Hydrogen = 1u, Oxygen = 16u), calculate the molecular mass of water (H₂O).

A) 17 u B) 18 u C) 19 u D) 32 u

10. When writing the chemical formula for a compound consisting of a metal and a non-metal, where is the symbol of the metal written?

A) On the right side B) On the left side C) It can be written on either side D) Only in brackets

Atoms and Molecules - Class 9 Science Quiz

A Quiz for CBSE Class 9 Science Students (Set 1)

1. According to the Law of Conservation of Mass, what happens to mass in a chemical reaction?

2. In a water molecule, what is the ratio by mass of hydrogen to oxygen, irrespective of its source?

3. Which of the following is a postulate of Dalton's atomic theory?

4. Which ancient Greek philosopher called the indivisible particles of matter 'atoms'?

5. In 1961, which isotope was chosen as the standard reference for measuring atomic masses universally?

6. What is the atomicity of a molecule of oxygen (O₂)?

7. A negatively charged ion is called a/an:

8. Which international scientific organisation approves names of elements, symbols, and units?

9. Using the atomic masses provided in the PDF (Hydrogen = 1u, Oxygen = 16u), calculate the molecular mass of water (H₂O).

10. When writing the chemical formula for a compound consisting of a metal and a non-metal, where is the symbol of the metal written?

Quiz Results

Atoms and Molecules Quizzes

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Atoms and Molecules - Class 9 Science Quiz

A Quiz for CBSE Class 9 Science Students (Set 1)

1. According to the Law of Conservation of Mass, what happens to mass in a chemical reaction? Read

2. In a water molecule, what is the ratio by mass of hydrogen to oxygen, irrespective of its source? Read

3. Which of the following is a postulate of Dalton's atomic theory? Read

4. Which ancient Greek philosopher called the indivisible particles of matter 'atoms'? Read

5. In 1961, which isotope was chosen as the standard reference for measuring atomic masses universally? Read

6. What is the atomicity of a molecule of oxygen (O2)? Read

7. A negatively charged ion is called a/an: Read

8. Which international scientific organisation approves names of elements, symbols, and units? Read

9. Using the atomic masses provided in the PDF (Hydrogen = 1u, Oxygen = 16u), calculate the molecular mass of water (H2O). Read

10. When writing the chemical formula for a compound consisting of a metal and a non-metal, where is the symbol of the metal written? Read

Quiz Results

Atoms and Molecules Quizzes

Was this page helpful?

1. According to the Law of Conservation of Mass, what happens to mass in a chemical reaction?

2. In a water molecule, what is the ratio by mass of hydrogen to oxygen, irrespective of its source?

3. Which of the following is a postulate of Dalton's atomic theory?

4. Which ancient Greek philosopher called the indivisible particles of matter 'atoms'?

5. In 1961, which isotope was chosen as the standard reference for measuring atomic masses universally?

6. What is the atomicity of a molecule of oxygen (O₂)?

7. A negatively charged ion is called a/an:

8. Which international scientific organisation approves names of elements, symbols, and units?

9. Using the atomic masses provided in the PDF (Hydrogen = 1u, Oxygen = 16u), calculate the molecular mass of water (H₂O).

10. When writing the chemical formula for a compound consisting of a metal and a non-metal, where is the symbol of the metal written?