Characteristics of a medium wave. They are <span>Wavelengths in this band are long enough that radio waves are not blocked by buildings and hills and can propagate beyond the horizon following the curvature of the Earth; this is called the </span>ground wave<span>. Practical groundwave reception typically extends to 200–300 miles, with longer distances over terrain with higher </span>ground conductivity<span>, and greatest distances over salt water. Most broadcast stations use ground wave to cover their listening area. Hope this helps. :)</span>
Answer:
evaporation.
evaporation is the process by which water changes from liquid to a gas or vapor.
Answer:
See explanation
Explanation:
If the spot in TLC is below the solvent front, it will be observed that the spot, instead of being separated by the solvent as expected, will just dissolve away in the solvent and zero actual separation of the mixture is achieved.
If the solute is dissolved away instead of being separated by the solvent, then the experiment fails because no actual separation of the mixture is achieved.
Hence, in TLC, the spot must be applied above the solvent front so that the capillary movement of the solvent through the plate can lead to the eventual separation of the components of the mixture since the various components of the mixture will travel at different speeds through the plate.
Also, if the solvent is above the spot, the solvent may evaporate selectively from the points above the spot while separation is ongoing.
Answer: Oxygen usually forms two covalent bonds or a covalent double bond.
Explanation:
A covalent bond is formed by the sharing of 2 electrons, 1 electron from each of the atoms sharing their electrons.
The number of bonds that each element can form depends on the number of valence (outermost) electrons it contains. Oxygen has 6 electrons in its valence shell and needs 2 more electrons thereby forming a double bond.