What is chyme?

Explanation

### Step-by-Step Solution:

1. **Definition of Chyme**: Chyme is a semi-fluid mass that forms in the stomach during the digestion of food. It is not completely liquid nor solid, but rather a mixture of both.

2. **Composition of Chyme**: Chyme consists of partly digested food, water, hydrochloric acid, and various digestive enzymes. The presence of these components indicates that the food has undergone some level of processing.

3. **Formation of Chyme**: The formation of chyme occurs due to both mechanical and chemical breakdown of food in the stomach. Mechanical breakdown involves the physical mixing and churning of food, while chemical breakdown involves the action of digestive enzymes and acids.

...