We are going to use table salt, NaCl as an example.
(s) = solid, eg the salt you put on your food is a crystalline solid.
(l) = liquid, if you melt salt it take on a liquid form
(g) = gaseous, if you put enough energy in the salt will turn into a gas.
(aq) = aqueous, meaning in water or another solvent. If you put some table salt in water and stir it, it will dissolve, the NaCl molecules dont get destroyed but they dissolve becoming part of the liquid.
When you have both of these ( The periodic table of elements and the formula of your compound) you are able to calculate the R.M.M ( Relative atomic mass) of that compound.
For example the formula of a NaCl ( Table salt ) has the elemnt Na and Cl.
We look at the atomic mass of both of these compounds
Na - 23
Cl - 35.5
R.M.M = 23 +35.5 = 58.5
Hope this helps :).
Answer:
A. Chemical because there alot of chemicals that contains energy such as Carbohydrates which fruit and vegetables contain.