Modern Atomic Theory states that matter is composed of small, indivisible particles called atoms.
Concept #1: The Conservation of Matter
The Law of Conservation of Mass states that matter can neither be created nor destroyed, all that happens is that it changes forms.
Concept #2: Law of Definite Proportions
No matter where you obtain a compound, whether it’s from a lab experiment or from collection out in the field, the ratio of elements in it will remain constant.
Concept #3: Law of Multiple Proportions
When element A and element B combine they can form different compounds in different ratios to one another. Dividing these different ratios should generate whole number answers.
Example #1: A 15.39 g sample of iodine reacts with 62.92 g of chlorine to form iodine pentachloride, ICl5. If iodine pentachloride is the only product formed calculate its mass.
Example #2: Two samples sodium fluoride decompose into their constituent elements. The first sample produces 15.8 kg of sodium and 20.1 kg of fluorine. If the second sample produces 192.0 g of sodium, how many grams of fluorine were also produced?
Practice: Which of the following is an example of the law of multiple proportions?