To determine which of the four substances is a solid, we need to analyze the descriptions of their atomic behaviors. Let's break it down step by step:
1. Object 1: Slide past each other
- This description is characteristic of a liquid. In liquids, atoms or molecules slide past each other, which allows the substance to flow.
2. Object 2: Are very viscous
- High viscosity usually indicates a thick, slow-flowing substance, but it can still be a liquid. This description doesn't suggest solidity.
3. Object 3: Forma crystal
- The formation of crystals is a specific property of solids. In the solid state, atoms are arranged in a fixed, repeating pattern, forming a crystalline structure.
4. Object 4: Spread out to fill their container
- This description is characteristic of gases. In the gaseous state, atoms or molecules move freely and expand to fill the container they are in.
From the above analysis, it is clear that the substance that is a solid is the one described as "Forma crystal." Therefore,
Object 3 is a solid.
