41. Which of the following is a non-metal?

A) Magnesium
B) Chlorine
C) Aluminum
D) Zinc
Answer: B) Chlorine

42. What is the boiling point of water in Celsius?

A) 0°C
B) 50°C
C) 100°C
D) 150°C
Answer: C) 100°C

43. Which of the following is an example of an exothermic reaction?

A) Melting of ice
B) Boiling of water
C) Combustion of gasoline
D) Photosynthesis
Answer: C) Combustion of gasoline

44. Which of the following is the lightest element?

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

45. Which of the following is a metalloid?

A) Silicon
B) Carbon
C

) Oxygen
D) Phosphorus
Answer: A) Silicon

46. The process of a solid changing directly to a gas is called:

A) Melting
B) Sublimation
C) Evaporation
D) Condensation
Answer: B) Sublimation

47. Which of the following is a polyatomic ion?

A) Na+
B) Cl-
C) OH-
D) Mg2+
Answer: C) OH-

48. What is the chemical formula of glucose?

A) C6H12O6
B) C12H22O11
C) C2H5OH
D) CH3COOH
Answer: A) C6H12O6

49. Which of the following is a homogeneous mixture?

A) Sand and water
B) Oil and water
C) Saltwater
D) Air and dust
Answer: C) Saltwater

50. Which of the following particles is found in the nucleus of an atom?

A) Electron
B) Proton
C) Neutron
D) Both B and C
Answer: D) Both B and C