The law of definite proportions states that a chemical compound always contains exactly the same proportion of elements by mass. The French chemist Joseph Proust conducted several experiments between 1798 and 1804 to make this discovery. At the time (before Dalton had proposed his atomic theory), the law was controversial.

This activity is designed for the TI-Nspire handheld and intends to help students increase their understanding of this law using evidence based reasoning.

Two files provide information on this activity. Word documents for teacher and for students show each TI-NSpire screen and offer commentary. Teacher documents (LDPT) show sample data sets and offer suggested answers to questions. The student document (LDPS) leaves questions unanswered and data sets empty.

Attached at the .tns files for this activity. Two files are included. The teacher files include data sets. The student files have empty data sets.

Post activity information is included in the documents and .tns files already uploaded to the site.