Questions et reponses d'entretien

Example:

Oxygen (O2) is a molecule composed of two oxygen atoms.

Example:

A solution with a pH of 7 is neutral, like pure water.

Example:

Water (H2O) is a compound composed of hydrogen and oxygen.

Example:

Enzymes act as catalysts in biological systems, facilitating metabolic reactions.

Example:

Carbon-14 is used in radiocarbon dating to determine the age of archaeological artifacts.

Example:

Elements in the same column (group) of the periodic table share similar chemical properties.

Example:

Sodium (Na+) is a cation, while chlorine (Cl-) is an anion.

Example:

In the reaction Zn + CuSO4 → ZnSO4 + Cu, zinc (Zn) undergoes oxidation, and copper (Cu) undergoes reduction.

Example:

One mole of water contains Avogadro's number of water molecules, which is approximately 6.022 x 10^23.

Example:

In the balanced equation 2H2 + O2 → 2H2O, the stoichiometric coefficients are 2, 1, and 2, respectively.

Example:

Carbon-12 has six protons and six neutrons in its nucleus.

Example:

Formaldehyde is an aldehyde, while acetone is a ketone.

Example:

Polyethylene is a polymer composed of repeating ethylene monomers.

Example:

In the Rutherford model, most of the atom's mass is concentrated in the nucleus.