21. Which of the following solutions is a good conductor of electricity?

A) Sugar solution
B) Distilled water
C) Saltwater
D) Alcohol
Answer: C) Saltwater

22. Which of the following has the highest ionization energy?

A) Lithium
B) Sodium
C) Potassium
D) Fluorine
Answer: D) Fluorine

23. What is the charge of an electron?

A) +1
B) -1
C) 0
D) +2
Answer: B) -1

24. Which of the following is not a state of matter?

A) Solid
B) Liquid
C) Gas
D) Plasma
Answer: D) Plasma

25. Which element is known as the “king of chemicals”?

A) Sulfur
B) Chlorine
C) Hydrogen
D) Sulfuric Acid
Answer: D) Sulfuric Acid

26. What is the primary component of natural gas?

A) Ethane
B) Butane
C) Methane
D) Propane
Answer: C) Methane

27. Which element has the atomic number 1?

A) Helium
B) Lithium
C) Hydrogen
D) Oxygen
Answer: C) Hydrogen

28. The atomic mass of an element is determined by the number of:

A) Protons
B) Neutrons
C) Electrons
D) Protons and Neutrons
Answer: D) Protons and Neutrons

29. Which type of reaction involves the exchange of ions between two compounds?

A) Decomposition
B) Synthesis
C) Single Replacement
D) Double Replacement
Answer: D) Double Replacement

30. Which of the following is a strong acid?

A) H2O
B) HCl
C) NH3
D) NaOH
Answer: B) HCl