<span>Activity series of metals. it is a series of metals based on their reactivity from highest to lowest. Potassium occupies the top most level of reactivity. The reactivity means the ability to displace hydrogen gas from water and acid solutions.</span>
<span>Energy is absorbed and then released to form an emission line.
When electrons absorb energy they increase there energy level. This is only temporary and the excited electron then relaxes back down to its original energy level releasing energy.
The energy is released in form of EM radiation of a specific frequency depending on the element and how many energy levels the electron relaxes.
This forms an emission line.</span><span />
Grease and non-polar too, so the <span>tetrachloroethylene would be a solvent.</span>
Just simply... they both are energy.
Use a bow and arrow as an example:
When you pull back an arrow, potential energy or PE is stored in the string and the limbs of the bow.
When you release the the arrow, energy is being transferred from the bow to the arrow. The arrow now has kinetic energy or KE, this means that the energy is being used by the arrow.
