NTS Everyday Science Concepts 2 — Questions and Answers
Question 1: Which vitamin is produced by the human body 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 when exposed to ultraviolet B (UVB) radiation from sunlight.
Vitamin D is unique because the human body can produce it when skin is exposed to UVB rays from sunlight. The process converts 7-dehydrocholesterol in the skin to vitamin D3. This vitamin is essential for calcium absorption and bone health. Vitamin D deficiency is common in regions with limited sunlight. Basic biology and health science are tested in NTS.
Question 2: What is the chemical formula of water?
- HO₂
- H₂O (Correct answer)
- H₂O₂
- OH
Correct answer: H₂O
Water's chemical formula is H₂O, consisting of two hydrogen atoms and one oxygen atom.
Water (H₂O) is composed of two hydrogen atoms covalently bonded to one oxygen atom. H₂O₂ is hydrogen peroxide, a different compound. Water is essential for life and covers about 71% of Earth's surface. Basic chemical formulas are part of NTS everyday science.
Question 3: Which planet is known as the 'Red Planet'?
- Jupiter
- Venus
- Mars (Correct answer)
- Saturn
Correct answer: Mars
Mars is called the Red Planet due to iron oxide (rust) on its surface giving it a reddish appearance.
Mars appears red because its surface contains iron oxide (Fe₂O₃), commonly known as rust. Mars is the fourth planet from the Sun and has been explored by multiple rovers including Curiosity and Perseverance. It has two small moons: Phobos and Deimos. Solar system knowledge is part of NTS general science.
Question 4: What is the boiling point of water at sea level?
- 90°C
- 95°C
- 100°C (Correct answer)
- 110°C
Correct answer: 100°C
Water boils at 100°C (212°F) at standard atmospheric pressure at sea level.
At standard atmospheric pressure (1 atm or 101.325 kPa) at sea level, water boils at exactly 100°C (212°F). This temperature decreases at higher altitudes due to lower atmospheric pressure. The Celsius scale was originally defined by the freezing point (0°C) and boiling point (100°C) of water. Basic physics concepts are tested in NTS everyday science.
Question 5: Which gas do plants absorb during photosynthesis?
- Oxygen
- Nitrogen
- Carbon Dioxide (Correct answer)
- Hydrogen
Correct answer: Carbon Dioxide
Plants absorb carbon dioxide (CO₂) from the atmosphere and use it with water and sunlight to produce glucose and oxygen.
During photosynthesis, plants absorb carbon dioxide (CO₂) through their stomata (leaf pores). Using sunlight energy captured by chlorophyll, CO₂ and water (H₂O) are converted into glucose (C₆H₁₂O₆) and oxygen (O₂). The equation: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂. Photosynthesis is a core NTS science topic.
Question 6: What is the hardest natural substance on Earth?
- Gold
- Iron
- Diamond (Correct answer)
- Platinum
Correct answer: Diamond
Diamond is the hardest known natural material, scoring 10 on the Mohs hardness scale.
Diamond scores 10 on the Mohs scale of mineral hardness, making it the hardest known natural substance. It is composed of carbon atoms arranged in a crystal structure called diamond cubic. Diamond's hardness makes it useful for cutting, grinding, and drilling tools. Material science basics are included in NTS everyday science.
NTS Everyday Science Concepts 2
Which vitamin is produced by the human body when exposed to sunlight?