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).
1 The depth of the gravel can vary, but should be at least 4-6 inches. To determine this measurement in feet, divide the number of inches by 12 (for example, 6 inches is 0.5 feet).  If you plan to do 2-3 layers, each layer will need to be 4-6 inches thick, so you will to calculate each layer separately.