The answer is the D. "Observation" is not a variable in an experiment.
Explanation: Research variables are factors that can be manipulated, measured or those that we try to explain through other variables. "Observation" is not a variable in an experiment, but it is the first step and fundamental part in the scientific method, in which the experiments are contained (experimentation stage). Observation is the information recorded during an experiment, obtained through the senses or through the registration of information on scientific instruments.
The density of any material can be calculated using the following rule:
density = mass / volume
Therefore,
mass = density x volume
Density of air is 0.001184 g/mL. To convert it to <span> kg/m^3, multiply by 1000.
Density of air = </span>0.001184 g/mL x 1000 = 1.184 kg/m^3
Now, let's calculate the volume of air. The volume of air will be exactly equal to the volume of the room that the air occupies.
volume of air = volume of room = length x width x height
volume of air = 4 x 2.38 x 3.77 = 35.8904 m^3
Finally, we will substitute in the previously mentioned rule to calculate the mass as follows:
mass = density x volume = 1.184 x 35.8904 = 42.494 kg.
Answer:
Solid will sublime into a gas.
Explanation:
Triple point is a temperature where the three states of a substance coexist.
If the pressure is lower than the triple point, the substance does not exist as a liquid, so it is impossible that solid melts, or that the solid remains as a solid.
Liquid state is not stable.