Especialidades JA/Arena/Respuestas
1
2
3
Sand is formed through two primary processes - Physical and Chemical.
4
Sand is composed of inorganic material, even if it had biogenic origins (shells, coral, diatoms, foraminfera). Soil, however, is made up of sand, silt, clay, and organic humus (broken down plant and animal matter).
5
Shape
The shape of a grain of sand can tell us about its history. Rounded grains are those which are relatively old, the rounding being caused by the grain getting blown around by wind or pushed around by water. Grains with more angular surface are relatively young, not having had time to get rounded by the forces of nature.
6
6a
6b
6c
6d
6e
6f
6g
6h
6i
6j
7
Using a hand lens or a microscope, examine the sand grains, looking for the features described in requirement 5 (shape, surface, grain fracture, and grain size). You can also note its color and its variability are all the grains the same size? Are they all the same shape, or are there big differences from one grain to the next?
8
de cierto te bendeciré y multiplicaré tu descendencia como las estrellas del cielo y como la arena que está a la orilla del mar; tu descendencia se adueñará de las puertas de sus enemigos.
- Pesada es la piedra y la arena pesa,
- pero más pesada que ambas es la ira del necio.
- ¡Cuán preciosos, Dios, me son tus pensamientos!
- ¡Cuán grande es la suma de ellos!
- Si los enumero, se multiplican más que la arena.
- Yo despierto y aún estoy contigo.