Explanation

Cl-CH₂-COOH (chloroacetic acid) is the strongest because the electronegative chlorine atom withdraws electrons, increasing acidity.

This stabilizes the conjugate base, making it a stronger acid than formic acid (HCOOH) or acetic acid (CH₃COOH).

Explanation

NO₂ is a reddish-brown gas that gives photochemical smog its characteristic brownish color.

It is formed by the reaction of NO with oxygen in sunlight.

It is a major pollutant in urban smog.

Explanation

The reaction where larger hydrocarbons (like C₈H₁₈) break into smaller ones (like C₃H₆ and fragments) is called cracking.

Cracking is commonly used in the petroleum industry to produce smaller, more useful hydrocarbons such as alkenes and gasoline.

Explanation

Proteins and peptides, when hydrolyzed, break down into α-amino acids, which are the building blocks of proteins.

In α-amino acids, the amino group (–NH₂) is attached to the α-carbon, the carbon next to the carboxyl group.

Explanation

Anthracite is the hardest and most mature form of coal, containing the highest percentage of carbon (about 86–98%).

It burns cleanly with very little smoke.

It has the highest energy content among coal types.

Explanation

Clay is a boy of nine or ten.

He needs money to bring his father home, and to buy his mother a present.

His father has left home because of poverty.

Clay needs money to help his parents and bring happiness back to his home. 

So, Clay is going to the beach to look for stuff.

Explanation

In an amino acid, a proton transfers from the carboxylic group (–COOH) to the amino group (–NH₂), forming a dipolar ion.

This ion with both positive and negative charges but overall neutral is called a zwitter ion.

Explanation

Nitric oxide (NO) is a highly reactive gas with a short atmospheric lifetime.

Its residence time is typically a few hours, due to rapid chemical reactions with other atmospheric compounds.