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

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

Acetic acid is used to produce cellulose acetate, a key component in making synthetic fibers like rayon.

It acts as a solvent and reactant in the fiber manufacturing process.

Explanation

Octyl acetate is a natural ester known for its fruity, orange-like aroma.

It is commonly used in flavorings and perfumes to mimic orange scent.

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

Chlorofluorocarbons (CFCs) release chlorine atoms in the stratosphere, which break down ozone (O₃) molecules.

This reaction is the main cause of ozone layer depletion.

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

Methane (CH₄) is a stable greenhouse gas with a relatively long atmospheric lifetime.

Its mean residence time in the atmosphere is approximately 3 to 7 years before it reacts or breaks down.

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.

Explanation

Across the periods of the periodic table, the shielding effect remains relatively constant.

This is because the number of inner shell electrons, which are responsible for shielding, does not change as you move across a period.