Question

1. which model contains only one compound?

Explanation:

Step1: Recall compound definition

A compound is a substance made of two or more different elements chemically bonded. A model with only one compound has identical molecules, each with multiple elements.

Step2: Analyze each model (S, Q, R, T)

• Model S: Likely has multiple substances (mix of elements/compounds).
• Model Q: May have single - type molecules? No, probably elements.
• Model R: Maybe a single element (all same atoms).
• Model T: (Assume) Molecules with two different elements, all same (one compound).

Answer:

T (Assuming T is the model with identical compound molecules. If labels are as per typical problems, the correct model is the one with all molecules of the same compound, e.g., if T is that, then T. If the models are labeled as per the image, the right - most or the one with uniform compound - like molecules.)