______state of matter is incompressible.

Explanation

To answer the question "______ state of matter is incompressible," we can follow these steps:

### Step 1: Understand the states of matter
There are three primary states of matter: solids, liquids, and gases. Each state has different properties.

### Step 2: Define incompressibility
Incompressibility refers to the ability of a substance to resist changes in volume when pressure is applied.

### Step 3: Analyze the properties of each state
- **Solids**: Solids have tightly packed particles and strong intermolecular forces, making them incompressible.
- **Liquids**: Liquids have particles that are close together but can move past each other. They are less compressible than gases but more compressible than solids.
- **Gases**: Gases have widely spaced particles and weak intermolecular forces, making them highly compressible.

### Step 4: Identify the incompressible state
From the analysis, we can conclude that solids are the state of matter that is incompressible due to their tightly packed structure and strong intermolecular forces.

### Final Answer
The state of matter that is incompressible is **solid**.

---