Which term describes different forms of the same element in the same physical state?

Which term describes different forms of the same element in the same physical state?

• A. Isotopes
• B. Compounds
• C. Mixtures
• D. Allotropes

Answer: (D)

Allotropes are different forms of the same element that occur in the same phase, made possible by different arrangements of the atoms. This means the element is the same, but the way its atoms bond or are structured changes, giving distinct properties. For example, carbon can be solid as diamond or as graphite, two different allotropes with very different hardness and structures. Oxygen also has allotropes: O2 and O3 (ozone) are both gases, yet they are different forms of oxygen due to different bonding. This idea is distinct from isotopes (same element, different neutron count, which changes mass), compounds (combinations of different elements bonded together), and mixtures (physical blends of substances). So the term that fits is allotropes.

Allotropes are different forms of the same element that occur in the same phase, made possible by different arrangements of the atoms. This means the element is the same, but the way its atoms bond or are structured changes, giving distinct properties. For example, carbon can be solid as diamond or as graphite, two different allotropes with very different hardness and structures. Oxygen also has allotropes: O2 and O3 (ozone) are both gases, yet they are different forms of oxygen due to different bonding. This idea is distinct from isotopes (same element, different neutron count, which changes mass), compounds (combinations of different elements bonded together), and mixtures (physical blends of substances). So the term that fits is allotropes.