If a metal is bonded to carbon, they form ionic bonds. If a nonmetal forms a bond with carbon, they form covalent bond. Ionic bond requires metals to give away electrons to form cations and nonmetal to gain/accept electron to form anions. Covalent bond requires sharing of electrons between both elements. So if you meant exchange as in covalent bond, then no. Not many nonmetal elements form bonds with carbon as there are more metal elements in the periodic table.
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:
Energy is added (postive enthalpy)
Explanation:
Ice melting means solid turns into liquid. Solid is more stable than liquid thus you must put in energy to weaken the forces of solid and turn it into liquid. Thus, you must put in energy to melt ice. This makes the enthalpy of the system to be positive.
Sodium potassium pump is an active pump which transfer sodium and potassium ions across the membrane with the expenditure of energy in the form of ATP.
This kind of pump is generally used in nerve cells.
The pump works against the concentration gradient as the pump moves three Na+ ions outside the cell and two K+ ions inside the cell, though there is a high concentration of Na+ outside the cell and a low concentration of K+ outside the cell.
