ANSWER: Correct Chapter 1 Question 7 Â­ True/False Part A A scientific theory is a tentative or untested explanation that is proposed to explain scientific observations. This preview has intentionally blurred sections.
Gravel /ËÉ¡rÃ¦vÉl/ is a loose aggregation of rock fragments. Gravel is classified by particle size range and includes size classes from granule- to boulder-sized fragments. In the Udden-Wentworth scale gravel is categorized into granular gravel (2 to 4 mm or 0.079 to 0.157 in) and pebble gravel (4 to 64 mm or 0.2 to 2.5 in).
Types of Soils. Soils are generally categorized as gravel, sand, silt and clay. Sand consists of particles from near 0.5mm to 5.0mm (about 1/4 inch) in diameter. Gravel ranges from near 5.0mm to 75mm (about 3 inches) in diameter. Anything larger is considered either a cobble or boulder. Silt and clay are fine grained.