Question

the image below is a 3-d model of ammonia (nh₃). what term best describes ammonia? a. element b. mixture c. atom d. molecule

Explanation:

• An element is a pure substance made of only one type of atom (e.g., O₂, Fe). NH₃ has N and H atoms, so not an element (eliminates A).
• A mixture is a combination of two or more substances (not chemically bonded). NH₃ is a single substance, so not a mixture (eliminates B).
• An atom is the smallest unit of an element. NH₃ is made of multiple atoms (1 N, 3 H) bonded together, so not an atom (eliminates C).
• A molecule is a group of two or more atoms (same or different) bonded together. NH₃ has 1 N and 3 H atoms covalently bonded, so it is a molecule.

Answer:

D. molecule