11. Which law states that mass is neither created nor destroyed in a chemical reaction?

A) Boyle’s Law
B) Charles’s Law
C) Law of Conservation of Mass
D) Law of Definite Proportions
Answer: C) Law of Conservation of Mass

12. What is the common name for sodium chloride?

A) Baking Soda
B) Table Salt
C) Vinegar
D) Sugar
Answer: B) Table Salt

13. What is the name of the element with the symbol ‘Fe’?

A) Lead
B) Fluorine
C) Iron
D) Zinc
Answer: C) Iron

14. Which of the following is a diatomic molecule?

A) CO2
B) H2O
C) O2
D) CH4
Answer: C) O2

15. What is the molar mass of water (H2O)?

A) 18 g/mol
B) 34 g/mol
C) 28 g/mol
D) 32 g/mol
Answer: A) 18 g/mol

16. Which of the following is an alkaline earth metal?

A) Sodium
B) Magnesium
C) Iron
D) Zinc
Answer: B) Magnesium

17. What is the oxidation state of sulfur in H2SO4?

A) +2
B) +4
C) +6
D) +8
Answer: C) +6

18. What is the most abundant element in the Earth’s atmosphere?

A) Oxygen
B) Nitrogen
C) Carbon Dioxide
D) Argon
Answer: B) Nitrogen

19. Which of the following is a halogen?

A) Oxygen
B) Bromine
C) Nitrogen
D) Helium
Answer: B) Bromine

20. What is the chemical formula of methane?

A) CH3
B) C2H4
C) CH4
D) C3H8
Answer: C) CH4