BECE Science 3 — Questions and Answers
Question 1: What is the process by which a liquid changes into a gas at its boiling point?
- Condensation
- Sublimation
- Evaporation
- Vaporization (Correct answer)
Correct answer: Vaporization
Vaporization (specifically boiling) is the process by which a liquid rapidly changes to a gas when heated to its boiling point.
Question 2: Which organ is primarily responsible for filtering waste from the blood?
- Lungs
- Heart
- Kidneys (Correct answer)
- Liver
Correct answer: Kidneys
The kidneys filter waste products and excess substances from the blood to produce urine, which is then excreted.
Question 3: What is the SI unit of force?
- Joule
- Watt
- Newton (Correct answer)
- Pascal
Correct answer: Newton
The Newton (N) is the SI unit of force, defined as the force needed to accelerate a 1 kg mass at 1 m/s².
Question 4: Which of the following is an example of a chemical change?
- Ice melting into water
- Sugar dissolving in water
- Wood burning (Correct answer)
- Glass breaking
Correct answer: Wood burning
Burning wood is a chemical change because it produces new substances (ash, carbon dioxide, water vapor) that cannot easily be reversed.
Question 5: How many chromosomes do normal human body cells contain?
- 23
- 46 (Correct answer)
- 48
- 92
Correct answer: 46
Normal human somatic (body) cells contain 46 chromosomes arranged in 23 pairs.
Question 6: What type of rock is formed from cooled and solidified magma?
- Sedimentary
- Metamorphic
- Igneous (Correct answer)
- Limestone
Correct answer: Igneous
Igneous rocks form when magma (molten rock) cools and solidifies, either underground or on the Earth's surface.
Question 7: Which vitamin is produced by the skin when exposed to sunlight?
- Vitamin A
- Vitamin B12
- Vitamin C
- Vitamin D (Correct answer)
Correct answer: Vitamin D
Vitamin D is synthesized in the skin through a photochemical reaction triggered by ultraviolet (UV) radiation from sunlight.
BECE Science 3
What is the process by which a liquid changes into a gas at its boiling point?