It is an open system.<span>
- Closed
system </span>is a physical system which allows to exchange energy <span>with
the </span>surrounding but not allows to exchange matter. <span>
- Isolated system </span>does not exchange either matter or energy with the external
environment.<span>
- Open system </span>is a type of physical system which allows to exchange both matter <span>and </span>energy with the surroundings.<span>
<span>Hence, Alex's
experimental setup which has an unsealed beaker is an open system.</span></span>
I think there are two choices that would be correct. The ideas by the Ancient Greeks that is least partially supported by scientific experiments are light is a stream of rays that comes with great velocity from the eyes of an observer and it is the result of rays that leave the eyes, reflect off an object, and interact with sunlight to become visible. It was the Greeks who laid out basic laws about reflection and refraction where they found that the angle of incidence is the same as the angle of reflection. They thought light rays came from the eye and that it travels towards the object which results to the objects as visible. This was called the concept of intromission.<span />
NaCl = n/V
<span>6.4M = n/0.80L </span>
<span>n= 5.12mol</span>
Unstable Isotopes, Source of Thermal Energy, Poses Health Problems.