Can someone tell me about Exothermic & Endothermic?

Question

Can someone tell me about Exothermic & Endothermic? I just want to know about it because later I have to do an Oral exam for my old class. I just want to know a little bit about it and I've looked it up but can't find it. Also can you tell me a little about the pH scale?

Answer 1

When two or more atoms are combined to make a molecule a certain amount of energy is required to hold them together. If less energy is required to hold them together than they bring to the reaction the excess energy will be released (exothermic as in exit?) and the combination will be warmer. If the atoms do not have the required energy to hold them together they will absorb energy from the surroundings (endothermic where endo means within) and the combination will cool. pH is a logarithmic scale of the concentration of hydrogen ions in a water solution where low pH is acid, 7.0 is neutral and high pH is alkaline.

Answer 2

Endothermic reactions absorb heat, exothermic reactions give off heat.
pH is the acidity of a solution in terms of the activity of hydrogen.
Aqueous solutions with pH values lower than 7 are considered acidic, while pH values higher than 7 are considered basic.

Answer 3

Exothermic= exo means exit or outside of
Endothermic= endo means inside of
Thermic= refers to heat
Therefore, exothermic would refer to heat outside often refering to heat outside of the body. Endothermic means internal heat, or heat within the body. Hope that helps

Ph= refers to acidity or base of a substance.

Answer 4

Exothermic + Endothermic:
http://chemistry.about.com/cs/generalchemistry/a/aa051903a.htm


The PH scale is the scale which tells you how the acidity of a substance. Look at this picture to give you an idea:
http://www.jacksonbottom.org/Monitoring/WQ_examples/pH Scale.gif


Good luck!
Lorna