Explanation

• The smallest unit of matter is an atom.

Structure of an Atom

• Nucleus: The central part made of heavy protons and neutrons.
• Electrons: Tiny, light particles that circle the nucleus.
• Protons: Particles with a positive charge.
• Neutrons: Particles with no electrical charge

Explanation

• Position: 2nd planet from the Sun.
• Distance: About 108 million km from the Sun.
• Order: Mercury → Venus → Earth.
• Temperature: Hottest planet in the Solar System.
• Reason: Thick atmosphere traps heat through the greenhouse effect.

Explanation

• Hydrogen and helium are the two lightest gases.
• Helium is the second most abundant element in the universe, after hydrogen.
• Helium has monatomic molecules.
• It is the lightest of all gases except hydrogen.
• Hydrogen is the lightest gas known.
• It provides the maximum lift for balloons due to its very low density.

Last updated question 17-02-2026

Explanation

• Discoverer: Alexander Fleming
• Year of discovery: 1928
• Place: St. Mary's Hospital, London
• First patient treated with penicillin: Albert Alexander
• Date of first treatment: 12 February 1941

Last verified on 14-09-2026

Explanation

• Carbon dioxide (CO₂) is used in fire extinguishers.
• It extinguishes fire by displacing oxygen and cooling the burning material.
• CO₂ fire extinguishers are especially effective for electrical and flammable liquid fires.
• Carbon dioxide is a colorless and non-flammable gas.
• It leaves no residue after use.

Explanation

• Amylase breaks down starch.
• Starch → Maltose + smaller sugars.
• Found in saliva and pancreatic juice.
• Salivary amylase starts starch digestion in the mouth

Explanation

• O⁻ (O Negative) is the universal donor blood group.
• It can be transfused to A, B, AB, and O blood groups.
• O⁻ blood lacks A, B, and Rh (D) antigens.

Additional information:

• Universal Recipient: AB⁺ (AB Positive)
• ABO Blood Groups: A, B, AB, O
• Rh Types: Positive (+) and Negative (−)
• Total Common Blood Groups: 8 (A⁺, A⁻, B⁺, B⁻, AB⁺, AB⁻, O⁺, O⁻)

Last verified on 14-07-2026

Explanation

• Light Year is the distance that light can travel in one year.
• The distance light travels in one year is known as light year.
• 1 light year is equal to 9.5 x 10¹²km.

Last verified on 30-03-2026

Explanation

• Vitamin C deficiency causes scurvy.
• It can cause bleeding/loose gums, easy bruising, and poor wound healing.
• Other signs include rough skin, corkscrew hair, and red spots around hair follicles.
• Rickets is mainly caused by Vitamin D deficiency.

Last verified on 13-09-2026

Explanation

• Cumulonimbus clouds are tall, dense clouds associated with thunderstorms.
• They can produce hail, heavy rain, lightning, and strong winds.
• Hail forms when strong updrafts inside these storm clouds carry water droplets upward, where they freeze.

Last verified on 09-09-2026