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 If you want to do a thicker or thinner layer of gravel than 4 inches, divide your surface area by that depth expressed as a fraction of a foot. 2  For instance, 6 inches is half of a foot, so you would divide by 2, while 2 inches is 1/6 of a foot, so you would divide by 6.