Question

a student studies two different atom arrangements.
arrangement 1 arrangement 2
diagrams of two atom arrangements
how can the student classify arrangements 1 and 2?

• arrangements 1 and 2 are compounds; compounds are composed of different types of atoms.
• arrangements 1 and 2 are elements; elements are made of atoms or molecules composed of the same kind of atoms.
• arrangement 1 is an element, and arrangement 2 is a mixture; an element is made of one atom, and a mixture is made of more than one atom.
• arrangement 1 is an element, and arrangement 2 is a compound; an element is made of one atom, and a compound is made of one molecule.

Explanation:

To classify the arrangements, we analyze the particle types:

• Arrangement 1: Contains only single, identical atoms (same kind of atom).
• Arrangement 2: Contains molecules, each made of two identical atoms (same kind of atom in each molecule).

An element is defined as a substance made of atoms or molecules with the same kind of atom. A compound requires different atom types, and a mixture requires different substances (neither applies here).

• The first option is wrong (compounds need different atoms).
• The second option is correct: Both are elements (arrangement 1: single atoms of the same kind; arrangement 2: molecules of the same kind of atom).
• The third option is wrong (arrangement 2 is not a mixture; it’s molecules of the same atom).
• The fourth option is wrong (arrangement 2 is not a compound, and the definition of element/molecule is incorrect).

Answer:

B. Arrangements 1 and 2 are elements; elements are made of atoms or molecules composed of the same kind of atoms.