- Physical Sciences
a relative measure of the mass contribution of each component in a compound. The percentage composition of a part of a compound is the percentage mass that the part contributes to the whole compound.
reactions that cause the surroundings to cool. Heat is taken in.
during a reaction a molecule reacts with water to form ions (to separate into ions).
variation in a repetitive way as you move through the periodic table vertically or horizontally...
reactions in which two or more molecules react to form one molecule.