Final answer:
The term for the lowest or base formula found from percentage composition is the Empirical Formula, which is different from the molecular formula and is essential for understanding the basic proportion of elements in a compound. Option c.
Step-by-step explanation:
The term used to describe the lowest or base formula found from percentage composition is C) Empirical Formula. An empirical formula represents the simplest whole-number ratio of the elements in a compound. For instance, the molecular formula for glucose is C6H12O6, which can be simplified to the empirical formula CH2O. This empirical formula indicates the smallest integer ratio of the elements present in the compound. It is distinct from the molecular formula which represents the actual number of atoms of each element in a molecule of the compound. To convert an empirical formula to a molecular formula, the molar mass of the compound must be known.
A theoretical yield is the calculated maximum amount of product expected from a chemical reaction, based on the stoichiometry of the reaction. The actual yield is the amount of product actually obtained from the reaction, which can be less due to various practical factors. The percent yield is the ratio of actual yield to theoretical yield expressed as a percentage and is a measure of efficiency for a reaction.