Answer;
-B3
Explanation;
Refrigerants are divided into two groups according to toxicity:
-Class A signifies refrigerants for which toxicity has not been identified at concentrations less than or equal to 400 ppm; and
-Class B signifies refrigerants for which there is evidence of toxicity at concentrations below 400 ppm.
They are also divided into three groups according to flammability:
-Class 1 indicates refrigerants that do not show flame propagation when tested in air at 21°C and 101 kPa;
-Class 2 indicates refrigerants having a lower flammability limit of more than 0.10 kg/m3 at 21°C and 101 kPa and a heat of combustion of less than 19 kJ/kg;
-Class 3 indicates refrigerants that are highly flammable as defined by a lower flammability limit of less than or equal to 0.10 kg/m3 at 21°C and 101 kPa or a heat of combustion greater than or equal to 19 kJ/kg.
-Therefore; the answer for the above question would be Class B and class 3.
Evolution is all about the
process of inheriting characteristics within a population change over
generation.
Only inherited traits
differences that can be passed on are acted upon evolution.
<span>In the study, the humans
select desirable traits that can be passed from one generation to another.</span>
Answer:
Mineral C
Explanation:
Mineral C can scratch apalite, due to its higher hardness, but can be scratched BY feldspar due to it being slightly lower than feldspar.
The heat from the bonfire is transferred to the student's hands mainly, but not exclusively, through the process of RADIATION.
There are three mechanisms or processes of heat transfer: conduction, convection, and ratiation.
Conduction is carreid out by contact; it requires that the two objects are touching each other. This is not the case.
Convection is the heat transferred by the movement of the fluids (liquids ang gases). In some extent this happens in this case, but it is not the dominant effect becasue air is not a very good conductor. Specially if there is not much air movement (wind).
Thermal radiation is carried out by electromagnetic waves. When there is a source of intense heat, like the fire, the heat is propagated by radiation.
Then really, the heat from the bonfire gets to the student's hands by convection and radiation, but as fire is very intense (its temperature is very high), and as long as the air is calmed, the dominant process is radiation. If there is wind, convection starts to be important.
Yes, the story surprised me very much. However, I don’t think these similarities are something the twins inherited, I think they are coincidences. You can’t inherit the same wife or other similarity that are not decided by genes.
