Physical State of Matter
The physical state of matter refers to whether a substance is a solid, liquid, or gas. This state is determined by a combination of factors.

Intermolecular Forces
One of the main factors that determines the physical state of matter is the strength of intermolecular forces. In solids, these forces are strong enough to hold the particles closely together in a fixed arrangement. In liquids, the forces are weaker, allowing the particles to move around but still stay close together. In gases, the forces are very weak, causing the particles to move freely and independently.

Temperature
Temperature also plays a crucial role in determining the physical state of matter. Increasing the temperature of a substance can provide enough energy to overcome the intermolecular forces holding the particles together. This can cause a solid to melt into a liquid or a liquid to evaporate into a gas.

Pressure
Pressure can also affect the physical state of matter, especially for gases. Increasing the pressure on a gas can force the particles closer together, causing the gas to condense into a liquid or solid.

Conclusion
In conclusion, the physical state of matter is determined by a combination of factors including intermolecular forces, temperature, and pressure. Understanding these factors can help explain why different substances exist in different states at different conditions.