<span>you have to find the differences of electronegativity for the atoms joined by the bond. if their diff is <0.4,
then it's non-polar
if it's between 0.4 to 1.7
then it's polar
1.7 and up it's ionic
Electronegativity values can be found on most periodic tables.</span>
If an atom suffers from a collision, that causes an electron to jump from a lower to higher state, it is called collisional excitation
Sawing a board in half is a physical change not a chemical change the board doesnt change wood or whatever material it is is still would still be wood
If it were burned it would be a chemical change but its properties stay the same atomically so thats why its not a chemical change.
