Glass & Soil Review

1. Glass & Soil Review

2. What is the state of matter of glass at room temperature?

3. It is an amorphous solid.

4. The main compounds in glass are __________.

5. Silicon Oxides & Metal Oxides

6. What is the name of the glass that is made by passing the molten glass through rollers?

7. Ordinary or rolled glass

8. Window glass is (more/less) dense than water.

9. More dense

10. The two most important physical properties of glass used for identification are:

11. Density and refractive index

12. True or False • Density is not homogeneous over sheet of glass

13. True

14. True or False, when glass shatters it is easy to reconstruct the original shape.

15. false

16. This type of glass involves a treatment where the glass is heated to 620oC and then cooled rapidly. What is the name of this glass?

17. Tempered or Safety Glass

18. Name the type of glass that is used for flat glass, container glass, and electric light bulbs.

19. Soda Lime Silicate

20. The fracture pattern of glass usually has __________ lines.

21. Conchoidal

22. This type of conchoidal line appears first when glass is fractured.

23. Radial

24. For a ______________ fracture, the perpendicular end, faces the surface on which the force originated.

25. concentric

26. In a forensic laboratory, a technique frequently used to determine the density of glass involves the use of ___________

27. Density – Gradient tubes

28. Stress marks on the edge of a radial crack near the point of impact are ___________ to the side on which the force was applied.

29. parallel

30. True or False A crater-shaped hole is narrower on the side where the projectile entered the glass.

31. True

32. True or False – It is easy to determine from the size and shape of a hole in glass, whether to was made by a bullet or some other projectile.

33. False

34. A piece of window glass is submerged in vegetable oil. The outline of the glass is visible. When light is shown behind the glass, a bright halo appears near the border of the glass. This bright halo is called a _________.

35. Becke line

36. ________ glass has a layer of plastic between two pieces of ordinary window glass.

37. Laminate or laminated

38. Name at least one out of three common problems associated with glass analysis (glass comparisons)

39. Find and measure properties • Associate one glass fragment with another • Minimize or eliminate other sources

40. The bending of light as it travels through one medium into another is known as ________.

41. Refraction

42. As light goes from the air into a liquid sample, the bending of light is due to a(n) ___________ in velocity of the light.

43. decrease

44. At 25oC the refractive index of water is 1.333. This means that light travels 1.333x __________ in a vacuum than in water.

45. Faster

46. ______________ solids • Refract a beam of light in two different light-ray components (wavelengths) • Results in double refraction

47. Crystalline

48. The numerical difference between these the two refractive indices of a crystalline solid is known as ________________.

49. Birefringence

50. This is an example of.. . . . . .