It is important to take note of th temperature in determining the density of a substance because this will set as a basis and will likely be a variable in the experiment because this will also contribute on the effects of the experiment and a basis of how the experiment has turned to be that way.
Answer:
an energy level represents the three dimensional space surrounding nucleus where electrons are most likely to be.
Explanation:

Electric current can be generated by moving a metal wire through a magnetic field. It is also different than static electricity, which is the accumulation of charges on a surface. <u>Electric generators rotate a coil</u> of wires through a magnetic field.
Answer:
Heating the mixture to a temperature above the boiling point of acetic acid, but below 100°C (the boiling point of water). The vapours from the acetic acid rise, and go into a tube. They are then condensed within the tube, and run off into a separate storage area. Because water can exist as a gas at pretty much any temperature above 0°C, it will result in an impure mixture, but repeatedly doing this will get the acetic acid to the desired purity.