Explanation

• The most abundant mineral in Earth’s mantle is Olivine.
• It dominates the upper mantle, especially in the form of peridotite rocks.
• Olivine is rich in magnesium and iron.
• It forms under high pressure and temperature conditions.

Last verified on 14-06-2026

Explanation

• The age of Earth’s oldest rocks is commonly determined using the Uranium-238 → Lead-206 radioactive decay system.
• Uranium-238 decays very slowly over billions of years.
• This long half-life makes it ideal for dating ancient geological materials.
• It helps scientists estimate Earth’s age (~4.5 billion years).

Last verified on 14-06-2026

Explanation

• Butter melts faster than ghee.
• Because it contains more water and milk solids, making its structure less stable.
• Water in butter lowers its melting stability at room temperature.
• This makes butter softer and quicker to melt.

Additional information:

• Ghee is almost pure fat with no water content.
• Ghee remains more stable because it is more refined.

Last verified on 14-06-2026

Explanation

• Zinc is commonly used in toothpaste.
• Because it helps reduce bacterial growth and controls bad breath.
• Zinc compounds (like zinc citrate or zinc chloride) kill or inhibit oral bacteria.
• It also helps reduce plaque formation.
• This improves overall oral hygiene.

Last verified on 14-06-2026

Explanation

• Soap lathers better in soft water because hard water contains calcium (Ca²⁺) and magnesium (Mg²⁺) ions that react with soap to form insoluble salts.
• These salts reduce soap’s ability to produce foam.
• Soft water does not contain these ions, so soap works fully.
• More soap remains active in soft water for lather formation.

Last verified on 14-06-2026