DVD A DVD player (or a CD-ROM reader) works by bouncing a laser off the surface of the
DVD, which acts like a mirror. An emitter sends out the light, which bounces off the DVD
and then is detected by a sensor. The diagram at right shows a DVD held parallel to the
surface of the DVD player, on wlich an emitter and a sensor are mounted.
Emitter
Sensor
DVD
a. The laser is supposed to bounce off the DVD at a 64° angle as shown in the diagram
above. For the laser to go directly into the sensor, at what angle does the emitter need
to send the laser beam? In other words, what does the measure of angle x have to
be? Justify your conclusion.
b. The diagram above shows two parts of the laser beam: the one coming out of the
emitter and the one that has bounced off the DVD. What is the angle (Zy) between
these beams? How do you know?

answer is: naturally occurring solid, inorganic compound or element is mineral.

minerals usually have crystalline form, that means than crystal constituents (atoms, molecules or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions.

for example magnetite is a mineral of iron oxide (fe₂o₃).

calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (caco₃).

dolomite is an   carbonate mineral composed of calcium magnesium carbonate (camg(co₃)₂).

a pan containing water is placed in a positio n where it is exposed to a 10 mile per hour wind. the pan contains a uniform depth of 1.27 cm of water, is quite wide, and has a length of 2.44 m in the wind direction. the water in the pan is at a constant temperature of 15.5 °c.

a. the law of proportion states the combination of 2 atoms in a specific ratio to produce multiple compounds such as the given statement of question ‘1st compound contains 88.8 % cu ’ indicates 88.8 g of cu is present along with 11.2 g oxygen in 100 g of compound whereas the statement ‘2st compound contains 79.9 % cu ’ indicates 79.9 g of cu is present along with 20.1 g oxygen in 100 g of compound

1st compound contains 88.8 g cu

for cu

m = 63 g /mol

atomic % = 88.8 /63 = 1.42

for o

m = 16 g /mol

atomic % = 11.2 /16 = 0.7

b. the emperical formula of 1st compound is

cu1.4o0.7

cu2o