Which process is defined as breaking down rocks into smaller pieces without changing the rocks' compositions? erosion
oxidation
chemical weathering
mechanical weathering

Mechanical weathering                                                                                  

Explanation: Mechanical weathering breaks rocks into smaller pieces without changing their composition. Ice wedging and abrasion are two important processes of mechanical weathering. Chemical weathering breaks down rocks by forming new minerals that are stable at the Earth's surface.

1. efficient use of space

2. elimination of groundwater contamination

3. energy generation

4. lower carbon footprint

blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart. as the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated.