What is the density of water?
💡 Explanation: Standard density
Average lifespan of red blood cells?
💡 Explanation: RBC lifespan is 120 days
What happens to pressure when gas volume decreases?
💡 Explanation: Boyle’s law
Who discovered the photoelectric effect?
💡 Explanation: Einstein won Nobel Prize
What percentage of the human body is water by weight?
💡 Explanation: Average water content is ~60%
What is the chemical formula of ozone?
💡 Explanation: Ozone contains three oxygen atoms
Which line divides the Earth into Northern and Southern Hemispheres?
💡 Explanation: Equator splits Earth into two halves
Which component of the human body primarily stores energy?
💡 Explanation: Fats act as the main energy reserve
What is the powerhouse of the cell?
💡 Explanation: Mitochondria generate most of the cell's supply of ATP, used as energy.
What gas do plants absorb from the atmosphere?
💡 Explanation: Plants absorb CO₂ and release oxygen through the process of photosynthesis.
Which planet is known as the Red Planet?
💡 Explanation: Mars is called the Red Planet because of the reddish appearance given by iron oxide on its surface.
What is the speed of light?
💡 Explanation: The speed of light in a vacuum is approximately 299,792 km/s.
What is the chemical symbol for water?
💡 Explanation: Water is composed of two hydrogen atoms and one oxygen atom — H₂O.
Which country has the most natural lakes?
💡 Explanation: Canada has more lakes than any other country, with about 60% of the world's lakes.
What is the smallest country in the world?
💡 Explanation: Vatican City, with an area of about 0.44 km², is the smallest country in the world.