Explanation

• The value 332 m/s is measured under standard atmospheric conditions.

Additional information:

• Speed of sound in air at 20°C ≈ 343 m/s.
• Speed of sound is faster in solids than liquids and gases.

Examples:

• Air: ~332 m/s (0°C)
• Water: ~1,480 m/s
• Steel: ~5,100 m/s

Last verified on 21-07-2026

Explanation

• The Mantle is the middle layer located between the crust and the core.
• It is the thickest layer of the Earth.
• It is made of hot, semi-solid rock.
• Thickness of Mantle: About 2,900 km
• Earth's Average Radius: About 6,371 km

Additional information:

• The Earth has three main layers: Crust, Mantle, and Core.
• Outermost layer: Crust
• Innermost layer: Core

Last verified on 21-07-2026

Explanation

• Total Vertebrae: 33
• Cervical Vertebrae: 7
• Thoracic Vertebrae: 12
• Lumbar Vertebrae: 5
• Sacral Vertebrae: 5 (fused) and Coccygeal Vertebrae: 4 (fused)

Additional information:

• Total bones in an adult: 206
• Bones in a newborn: About 300
• Longest bone: Femur
• Shortest bone: Stapes
• Bones in the skull: 22
• Bones in one hand: 27

Last verified on 21-07-2026

Explanation

• Venus is called the Morning Star and Evening Star.
• It is the second closest planet to the Sun.
• It is the brightest planet and the hottest planet in the Solar System.
• It has no natural moon (satellite).
• It is also known as the "Black Planet".

Last verified on 21-07-2026

Explanation

• An Astronomical Unit (AU) is the average distance between the Earth and the Sun.
• It is a standard unit used to measure distances within the Solar System.
• 1 AU = 149,597,870.7 km
• 1 AU = 92,955,807.3 miles
• Light travels 1 AU in: About 8 minutes 20 seconds

Last verified on 21-07-2026

Explanation

• The Aorta is the largest artery in the human body.
• It carries oxygen-rich blood from the left ventricle of the heart to the rest of the body.
• It is the main artery of the systemic circulatory system.
• The aorta branches into smaller arteries to supply blood to all body organs except the lungs.

Additional information:

• Arterioles are the smallest branches of arteries.
• They carry oxygenated blood from arteries to the capillaries.
• Arterioles regulate blood flow and blood pressure by constricting or dilating.

Last verified on 21-07-2026

Explanation

• First Polio Vaccine Introduced: 1955
• Developer: Dr. Jonas Salk
• Type: Inactivated Polio Vaccine (IPV)
• Oral Polio Vaccine (OPV): 1961
• Developer of OPV: Dr. Albert Sabin

Last verified on 20-07-2026

Explanation

• Malaria is caused by the parasite Plasmodium.
• It is transmitted to humans through the bite of an infected female Anopheles mosquito.
• Malaria is a parasitic disease.
• It mainly affects the liver and red blood cells.
• Common symptoms include fever, chills, headache, and sweating.

Last verified on 11-07-2026

Explanation

• Saturn is the second-largest planet in the solar system.
• Ganymede (Moon of Jupiter) is the largest satellite in the solar system.

Planets and Natural Satellites:

1. Mercury: 0
2. Venus: 0
3. Earth: 1 (Moon)
4. Mars: 2 (Deimos, Phobos)
5. Jupiter: 95
6. Saturn: 274
7. Uranus: 27

Last verified on 02-05-2026

Explanation

• Mercury is the only elemental metal that at room temperature is Liquid.
• Mercury (Hg) is the only metal that remains liquid at room temperature (about 25°C).

Additional information:

• Chemical Symbol: Hg
• Atomic Number: 80
• Melting Point: −38.83°C
• Boiling Point: 356.73°C

Last verified on 20-07-2026