Explanation

• Glycerin (glycerol) is a colorless, odorless, and viscous liquid.
• It is commonly used in pharmaceuticals, cosmetics, and food products.

Additional information:

• Glycerin is non-toxic and safe in small quantities.
• It acts as a humectant, helping retain moisture.

Last verified on 20-01-2026

Explanation

• Carbon has a valency of 4, meaning it can form 4 covalent bonds with other atoms.
• This property allows carbon to form complex organic compounds.
• It is the backbone of all organic molecules.

Additional information:

Examples of Carbon Compounds (5):

1. Methane (CH₄)
2. Ethane (C₂H₆)
3. Glucose (C₆H₁₂O₆)
4. Ethanol (C₂H₅OH)
5. Carbon dioxide (CO₂)

Last verified on 19-01-2026

Explanation

Metalloids have properties of both metals and non-metals.

They can conduct electricity better than non-metals but worse than metals.

Examples include silicon, boron, and germanium.

Metalloids are widely used in semiconductors and electronics.

Their mixed properties make them important in modern technology.

Explanation

Explanation

Helium is the rarest, as it's present in much smaller trace amounts (around 5.2 ppm)

Oxygen: ~209,000 ppm (20.9%)

Carbon Dioxide: ~420 ppm (0.04%)

Neon: ~18 ppm (0.0018%)

Helium: ~5.2 ppm (0.00052%) 

Xenon is generally considered the rarest of the common noble gases,