It expands in the cracks (which I think is erosion) and it breaks the pavement because of the constant expansion and moving of pavement pushes it to break.
Answer:
Oxygen - Proportions increased as plants released this gas into the atmosphere.
Water Vapor - Proportions decreased as this lighter gas was blown away by solar winds.
Hydrogen - Proportions increased as this gas was released through volcanic eruptions.
Ammonia - Proportions decreased as it reacted with other elements to form nitrogen.
Carbon Dioxide - Proportions decreases as plants used this gas during photosynthesis.
