A thermodynamic process at constant pressure is called___________________ process.

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for the term used to describe a thermodynamic process that occurs at constant pressure.

2. **Defining the Term**: In thermodynamics, a process that occurs at constant pressure is specifically referred to as an "isobaric process."

3. **Characteristics of an Isobaric Process**:
- In an isobaric process, the pressure remains constant throughout the process.
- The heat transfer (denoted as ΔQ) is not equal to zero, meaning heat can be added or removed from the system.
- The internal energy change (denoted as ΔU) is also not equal to zero, indicating that the internal energy of the system can change during the process.

4. **Example of an Isobaric Process**: A common example of an isobaric process is the boiling of water to steam. During this process, the pressure remains constant while heat is added to convert water into steam.

5. **Conclusion**: Therefore, the answer to the question is that a thermodynamic process at constant pressure is called an **isobaric process**.